#include <iostream>
#include <sstream>
#include <iomanip>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <algorithm>
#include <numeric>
#include <iterator>
#include <functional>
#include <complex>
#include <queue>
#include <stack>
#include <cmath>
#include <cassert>
using namespace std;
typedef long long LL;
typedef long double LD;
typedef complex<double> CMP;
class ShoutterDiv1 { public:
int count(vector <string> s1000, vector <string> s100, vector <string> s10, vector <string> s1, vector <string> t1000, vector <string> t100, vector <string> t10, vector <string> t1)
{
vector<int> s;
{
string S1000 = accumulate(s1000.begin(), s1000.end(), string());
string S100 = accumulate(s100.begin() , s100.end() , string());
string S10 = accumulate(s10.begin() , s10.end() , string());
string S1 = accumulate(s1.begin() , s1.end() , string());
for(int i=0; i<S1.size(); ++i)
s.push_back(atoi((string(1, S1000[i])+S100[i]+S10[i]+S1[i]).c_str()));
}
vector<int> t;
{
string T1000 = accumulate(t1000.begin(), t1000.end(), string());
string T100 = accumulate(t100.begin(), t100.end(), string());
string T10 = accumulate(t10.begin(), t10.end(), string());
string T1 = accumulate(t1.begin(), t1.end(), string());
for(int i=0; i<T1.size(); ++i)
t.push_back(atoi((string(1, T1000[i])+T100[i]+T10[i]+T1[i]).c_str()));
}
vector<pair<int,int> > st;
for(int i=0; i<s.size(); ++i)
st.push_back(make_pair(s[i], t[i]));
sort(st.begin(), st.end());
return solve(st);
}
int solve(const vector<pair<int,int> >& st)
{
const int N = st.size();
int L = 99999; // the time first rabbit leaves.
int R = 0; // the time last rabbit comes.
for(int i=0; i<N; ++i) {
int l = st[i].first;
int r = st[i].second;
L = min(L, r);
R = max(R, l);
}
// fill [L,R] with minimum number of intervals.
// must include st[i] for each i.
int total = 0;
for(int i=0; i<N; ++i) {
int c = cost(st, N, i, L, R);
if(c==-1)
return -1;
total += c - 1;
}
return total;
}
int cost(const vector<pair<int,int> >& st, int N, int I, int L, int R)
{
bool I_used = false;
int covered = L;
int used = 0;
for(int ks=0; ks<N; )
{
int ke=ks;
while(ke<N && st[ke].first<=covered)
++ke;
if(ke==ks)
break;
if(ks<=I && I<ke && !I_used)
{
++used;
I_used = true;
covered = max(covered, st[I].second);
}
else
{
if(covered < R) {
int bestRight = 0;
for(int i=ks; i<ke; ++i) if(i!=I)
bestRight = max(bestRight, st[i].second);
if(covered < bestRight) {
++used;
covered = max(covered, bestRight);
}
}
ks = ke;
}
}
return (R<=covered ? used : -1);
}
};
// BEGIN CUT HERE
#include <ctime>
double start_time; string timer()
{ ostringstream os; os << " (" << int((clock()-start_time)/CLOCKS_PER_SEC*1000) << " msec)"; return os.str(); }
template<typename T> ostream& operator<<(ostream& os, const vector<T>& v)
{ os << "{ ";
for(typename vector<T>::const_iterator it=v.begin(); it!=v.end(); ++it)
os << '\"' << *it << '\"' << (it+1==v.end() ? "" : ", "); os << " }"; return os; }
void verify_case(const int& Expected, const int& Received) {
bool ok = (Expected == Received);
if(ok) cerr << "PASSED" << timer() << endl; else { cerr << "FAILED" << timer() << endl;
cerr << "\to: \"" << Expected << '\"' << endl << "\tx: \"" << Received << '\"' << endl; } }
#define CASE(N) {cerr << "Test Case #" << N << "..." << flush; start_time=clock();
#define END verify_case(_, ShoutterDiv1().count(s1000, s100, s10, s1, t1000, t100, t10, t1));}
int main(){
CASE(0)
string s1000_[] = {"22", "2"};
vector <string> s1000(s1000_, s1000_+sizeof(s1000_)/sizeof(*s1000_));
string s100_[] = {"00", "0"};
vector <string> s100(s100_, s100_+sizeof(s100_)/sizeof(*s100_));
string s10_[] = {"11", "1"};
vector <string> s10(s10_, s10_+sizeof(s10_)/sizeof(*s10_));
string s1_[] = {"21", "4"};
vector <string> s1(s1_, s1_+sizeof(s1_)/sizeof(*s1_));
string t1000_[] = {"22", "2"};
vector <string> t1000(t1000_, t1000_+sizeof(t1000_)/sizeof(*t1000_));
string t100_[] = {"00", "0"};
vector <string> t100(t100_, t100_+sizeof(t100_)/sizeof(*t100_));
string t10_[] = {"11", "1"};
vector <string> t10(t10_, t10_+sizeof(t10_)/sizeof(*t10_));
string t1_[] = {"43", "6"};
vector <string> t1(t1_, t1_+sizeof(t1_)/sizeof(*t1_));
int _ = 2;
END
CASE(1)
string s1000_[] = {"00"};
vector <string> s1000(s1000_, s1000_+sizeof(s1000_)/sizeof(*s1000_));
string s100_[] = {"00"};
vector <string> s100(s100_, s100_+sizeof(s100_)/sizeof(*s100_));
string s10_[] = {"00"};
vector <string> s10(s10_, s10_+sizeof(s10_)/sizeof(*s10_));
string s1_[] = {"13"};
vector <string> s1(s1_, s1_+sizeof(s1_)/sizeof(*s1_));
string t1000_[] = {"00"};
vector <string> t1000(t1000_, t1000_+sizeof(t1000_)/sizeof(*t1000_));
string t100_[] = {"00"};
vector <string> t100(t100_, t100_+sizeof(t100_)/sizeof(*t100_));
string t10_[] = {"00"};
vector <string> t10(t10_, t10_+sizeof(t10_)/sizeof(*t10_));
string t1_[] = {"24"};
vector <string> t1(t1_, t1_+sizeof(t1_)/sizeof(*t1_));
int _ = -1;
END
CASE(2)
string s1000_[] = {"0000"};
vector <string> s1000(s1000_, s1000_+sizeof(s1000_)/sizeof(*s1000_));
string s100_[] = {"0000"};
vector <string> s100(s100_, s100_+sizeof(s100_)/sizeof(*s100_));
string s10_[] = {"0000"};
vector <string> s10(s10_, s10_+sizeof(s10_)/sizeof(*s10_));
string s1_[] = {"1234"};
vector <string> s1(s1_, s1_+sizeof(s1_)/sizeof(*s1_));
string t1000_[] = {"0000"};
vector <string> t1000(t1000_, t1000_+sizeof(t1000_)/sizeof(*t1000_));
string t100_[] = {"0000"};
vector <string> t100(t100_, t100_+sizeof(t100_)/sizeof(*t100_));
string t10_[] = {"0000"};
vector <string> t10(t10_, t10_+sizeof(t10_)/sizeof(*t10_));
string t1_[] = {"2345"};
vector <string> t1(t1_, t1_+sizeof(t1_)/sizeof(*t1_));
int _ = 6;
END
CASE(3)
string s1000_[] = {"0000000000"};
vector <string> s1000(s1000_, s1000_+sizeof(s1000_)/sizeof(*s1000_));
string s100_[] = {"0000000000"};
vector <string> s100(s100_, s100_+sizeof(s100_)/sizeof(*s100_));
string s10_[] = {"0000000000"};
vector <string> s10(s10_, s10_+sizeof(s10_)/sizeof(*s10_));
string s1_[] = {"7626463146"};
vector <string> s1(s1_, s1_+sizeof(s1_)/sizeof(*s1_));
string t1000_[] = {"0000000000"};
vector <string> t1000(t1000_, t1000_+sizeof(t1000_)/sizeof(*t1000_));
string t100_[] = {"0000000000"};
vector <string> t100(t100_, t100_+sizeof(t100_)/sizeof(*t100_));
string t10_[] = {"0000000000"};
vector <string> t10(t10_, t10_+sizeof(t10_)/sizeof(*t10_));
string t1_[] = {"9927686479"};
vector <string> t1(t1_, t1_+sizeof(t1_)/sizeof(*t1_));
int _ = 18;
END
CASE(4)
string s1000_[] = {"00000000000000000000000000000000000000000000000000"};
vector <string> s1000(s1000_, s1000_+sizeof(s1000_)/sizeof(*s1000_));
string s100_[] = {"00000000000000000000000000000000000000000000000000"};
vector <string> s100(s100_, s100_+sizeof(s100_)/sizeof(*s100_));
string s10_[] = {"50353624751857130208544645495168271486083954769538"};
vector <string> s10(s10_, s10_+sizeof(s10_)/sizeof(*s10_));
string s1_[] = {"85748487990028258641117783760944852941545064635928"};
vector <string> s1(s1_, s1_+sizeof(s1_)/sizeof(*s1_));
string t1000_[] = {"00000000000000000000000000000000000000000000000000"};
vector <string> t1000(t1000_, t1000_+sizeof(t1000_)/sizeof(*t1000_));
string t100_[] = {"00000000000000000000000000000000000000000000000000"};
vector <string> t100(t100_, t100_+sizeof(t100_)/sizeof(*t100_));
string t10_[] = {"61465744851859252308555855596388482696094965779649"};
vector <string> t10(t10_, t10_+sizeof(t10_)/sizeof(*t10_));
string t1_[] = {"37620749792666153778227385275518278477865684777411"};
vector <string> t1(t1_, t1_+sizeof(t1_)/sizeof(*t1_));
int _ = 333;
END
/*
CASE(5)
string s1000_[] = ;
vector <string> s1000(s1000_, s1000_+sizeof(s1000_)/sizeof(*s1000_));
string s100_[] = ;
vector <string> s100(s100_, s100_+sizeof(s100_)/sizeof(*s100_));
string s10_[] = ;
vector <string> s10(s10_, s10_+sizeof(s10_)/sizeof(*s10_));
string s1_[] = ;
vector <string> s1(s1_, s1_+sizeof(s1_)/sizeof(*s1_));
string t1000_[] = ;
vector <string> t1000(t1000_, t1000_+sizeof(t1000_)/sizeof(*t1000_));
string t100_[] = ;
vector <string> t100(t100_, t100_+sizeof(t100_)/sizeof(*t100_));
string t10_[] = ;
vector <string> t10(t10_, t10_+sizeof(t10_)/sizeof(*t10_));
string t1_[] = ;
vector <string> t1(t1_, t1_+sizeof(t1_)/sizeof(*t1_));
int _ = ;
END
CASE(6)
string s1000_[] = ;
vector <string> s1000(s1000_, s1000_+sizeof(s1000_)/sizeof(*s1000_));
string s100_[] = ;
vector <string> s100(s100_, s100_+sizeof(s100_)/sizeof(*s100_));
string s10_[] = ;
vector <string> s10(s10_, s10_+sizeof(s10_)/sizeof(*s10_));
string s1_[] = ;
vector <string> s1(s1_, s1_+sizeof(s1_)/sizeof(*s1_));
string t1000_[] = ;
vector <string> t1000(t1000_, t1000_+sizeof(t1000_)/sizeof(*t1000_));
string t100_[] = ;
vector <string> t100(t100_, t100_+sizeof(t100_)/sizeof(*t100_));
string t10_[] = ;
vector <string> t10(t10_, t10_+sizeof(t10_)/sizeof(*t10_));
string t1_[] = ;
vector <string> t1(t1_, t1_+sizeof(t1_)/sizeof(*t1_));
int _ = ;
END
*/
}
// END CUT HERE