Floyd Warshall

#include<bits/stdc++.h>

using namespace std;
typedef long long int ll;
//#define isvowel(a) (a == 'a' || a == 'e' || a == 'i' || a == 'o' || a == 'u')
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define gcd __gcd
#define getl(s) getline(cin, s);
#define setpre(x) fixed << setprecision(x)
#define mset(a) memset(a, 0, sizeof(a))
#define endl '\n'
const int N=1050,M=1000000007;
const ll INF=1e18+7;
int main(){
    ios_base::sync_with_stdio(NULL); cin.tie(nullptr); cout.tie(nullptr);
//    freopen(".inp","r",stdin);
//    freopen(".out","w",stdout);
    ll n,m,q,x,y,z,graph[N][N];
    cin>>n>>m;
    for(int i=1;i<=n;++i){
        for(int j=1;j<=n;++j){
            if(i==j) graph[i][j]=0;
            else graph[i][j]=INF;
        }
    }
    for(int i=0;i<m;++i){
        cin>>x>>y>>z;
        graph[x][y]=z;
    }
    for(int k=1;k<=n;++k){
        for(int i=1;i<=n;++i){
            for(int j=1;j<=n;++j){
                graph[i][j]=min(graph[i][j],graph[i][k]+graph[k][j]);
            }
        }
    }
    for(int i=1;i<=n;++i){
        for(int j=1;j<=n;++j){
            if(graph[i][j]==INF) graph[i][j]=-1;
        }
    }
    cin>>q;
    while(q--){
        cin>>x>>y;
        cout<<graph[x][y]<<endl;
    }
    return 0;
}
/*
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INPUT:                            |
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OUTPUT:                           |
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*/