ostatnia bitwa

#include<bits/stdc++.h>
using namespace std;
int main(){
  long long n, m, q, INF =  LLONG_MAX;
  cin >> n >> m >> q;
  long long d[n][n];
  for(long long i = 0;i < n;i++)
    for(long long j = 0;j < n;j++){
      d[i][j] = INF;
      if(i == j)
        d[i][j] = 0;
    }
  for(long long i = 0, a, b, w;i < m;i++){
    cin >> a >> b >> w; a--; b--;
    d[a][b] = min(d[a][b], w);
  }
  for(long long k = 0; k < n; ++k) {
    for(long long i = 0; i < n; ++i) {
      for(long long j = 0; j < n; ++j){
        if(d[i][k] < INF && d[k][j] < INF)
          d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
      }
    }
  }
  for (long long i = 0; i < n; ++i) {
    for (long long j = 0; j < n; ++j) {
      for (long long t = 0; t < n; ++t) {
        if (d[i][t] < INF && d[t][t] < 0 && d[t][j] < INF){
          cout << "NIE";
          return 0;
        }
      }
    }
  }
  for(long long i = 0, a, b;i < q;i++){
    cin >> a >> b; a--; b--;
    if(d[a][b] == INF) cout << "NIE\n";
    else cout << d[a][b] << '\n';
  }
  cout << '\n';
}