#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>
#include <cstring>
#ifdef __GNUC__
#include <ext/hash_map>
#define unordered_map __gnu_cxx::hash_map
#else
#include <unordered_map>
#endif
using namespace std;
typedef long long LL;
typedef complex<double> CMP;
class ImportantSequence { public:
int getCount(vector <int> B, string operators)
{
vector< pair<LL,LL> > A;
A.push_back( make_pair(1,0) );
for(int i=0; i<B.size(); ++i)
{
LL a = A.back().first;
LL b = A.back().second;
LL c = B[i];
if( operators[i] == '+' ) {
// (ax+b) + (px+q) = c
A.push_back( make_pair(-a, c-b) );
} else {
// (ax+b) - (px+q) = c
A.push_back( make_pair(a, b-c) );
}
}
static const LL INF = (1LL<<62);
LL xMin = 1;
LL xMax = INF;
for(int i=0; i<A.size(); ++i)
{
LL a = A[i].first;
LL b = A[i].second;
// ax + b > 0
if( a == +1 ) {
// x > -b
xMin = max(xMin, -b+1);
} else {
// -x > -b == x < b
xMax = min(xMax, b-1);
}
}
if( xMax == INF )
return -1;
return (int)max(0LL, xMax-xMin+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(_, ImportantSequence().getCount(B, operators));}
int main(){
CASE(0)
int B_[] = {3, -1, 7};
vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_));
string operators = "+-+";
int _ = 2;
END
CASE(1)
int B_[] = {1};
vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_));
string operators = "-";
int _ = -1;
END
CASE(2)
int B_[] = {1};
vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_));
string operators = "+";
int _ = 0;
END
CASE(3)
int B_[] = {10};
vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_));
string operators = "+";
int _ = 9;
END
CASE(4)
int B_[] = {540, 2012, 540, 2012, 540, 2012, 540};
vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_));
string operators = "-+-+-+-";
int _ = 1471;
END
CASE(5)
int B_[] = {1000000000, 1000000000, 1000000000, 1000000000, 1000000000,
1000000000, 1000000000, 1000000000, 1000000000, 1000000000,
1000000000, 1000000000, 1000000000, 1000000000, 1000000000,
1000000000, 1000000000, 1000000000, 1000000000, 1000000000,
1000000000, 1000000000, 1000000000, 1000000000, 1000000000,
1000000000, 1000000000, 1000000000, 1000000000, 1000000000,
1000000000};
vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_));
string operators = "------------------------------+";
int _ = -1;
END
/*
CASE(6)
int B_[] = ;
vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_));
string operators = ;
int _ = ;
END
*/
}
// END CUT HERE