#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 <tuple>
using namespace std;
typedef long long LL;
typedef complex<double> CMP;
class Egalitarianism3 { public:
int maxCities(int n, vector <int> a, vector <int> b, vector <int> len)
{
if(n<=2)
return n;
const int INF = 0x3fffffff;
vector<vector<int>> d(n, vector<int>(n, INF));
for(int i=0; i<n; ++i)
d[i][i] = 0;
for(int i=0; i<a.size(); ++i) {
d[a[i]-1][b[i]-1] = len[i];
d[b[i]-1][a[i]-1] = len[i];
}
for(int k=0; k<n; ++k)
for(int i=0; i<n; ++i)
for(int j=0; j<n; ++j)
d[i][j] = min(d[i][j], d[i][k]+d[k][j]);
int best = 2;
for(int c=0; c<n; ++c) {
map<int, vector<int>> cand;
for(int v=0; v<n; ++v) if(v!=c) {
int rad = d[c][v];
bool ok = true;
for(int u: cand[rad])
if(d[v][u] != 2*rad)
ok = false;
if(ok) {
cand[rad].push_back(v);
best = max<int>(best, cand[rad].size());
}
}
}
return best;
}
};
// 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(_, Egalitarianism3().maxCities(n, a, b, len));}
int main(){
CASE(0)
int n = 4;
int a_[] = {1,1,1};
vector <int> a(a_, a_+sizeof(a_)/sizeof(*a_));
int b_[] = {2,3,4};
vector <int> b(b_, b_+sizeof(b_)/sizeof(*b_));
int len_[] = {1,1,1};
vector <int> len(len_, len_+sizeof(len_)/sizeof(*len_));
int _ = 3;
END
CASE(1)
int n = 6;
int a_[] = {1,2,3,2,3};
vector <int> a(a_, a_+sizeof(a_)/sizeof(*a_));
int b_[] = {2,3,4,5,6};
vector <int> b(b_, b_+sizeof(b_)/sizeof(*b_));
int len_[] = {2,1,3,2,3};
vector <int> len(len_, len_+sizeof(len_)/sizeof(*len_));
int _ = 3;
END
CASE(2)
int n = 10;
int a_[] = {1,1,1,1,1,1,1,1,1};
vector <int> a(a_, a_+sizeof(a_)/sizeof(*a_));
int b_[] = {2,3,4,5,6,7,8,9,10};
vector <int> b(b_, b_+sizeof(b_)/sizeof(*b_));
int len_[] = {1000,1000,1000,1000,1000,1000,1000,1000,1000};
vector <int> len(len_, len_+sizeof(len_)/sizeof(*len_));
int _ = 9;
END
CASE(3)
int n = 1;
vector <int> a;
vector <int> b;
vector <int> len;
int _ = 1;
END
/*
CASE(4)
int n = ;
int a_[] = ;
vector <int> a(a_, a_+sizeof(a_)/sizeof(*a_));
int b_[] = ;
vector <int> b(b_, b_+sizeof(b_)/sizeof(*b_));
int len_[] = ;
vector <int> len(len_, len_+sizeof(len_)/sizeof(*len_));
int _ = ;
END
CASE(5)
int n = ;
int a_[] = ;
vector <int> a(a_, a_+sizeof(a_)/sizeof(*a_));
int b_[] = ;
vector <int> b(b_, b_+sizeof(b_)/sizeof(*b_));
int len_[] = ;
vector <int> len(len_, len_+sizeof(len_)/sizeof(*len_));
int _ = ;
END
*/
}
// END CUT HERE