ЗОШ 1-k bfs OK

#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>
#include <string>
#include <stack>
#include <set>
#include <map>
#define pii pair <int,int>
using namespace std;
using ll = long long;
using ld = long double;
using db = double;
void cv(vector <int> &v){
    for (auto x: v) cout<<x<<' ';
    cout<<"\n";
}

void cvl(vector <ll> &v){
    for (auto x: v) cout<<x<<' ';
    cout<<"\n";
}


void cvv(vector <vector <int> > &v){
    for (auto x: v) cv(x);
    cout<<"\n";
}

int n,m;
const ld inf = 2e9;
const int mx_way = 5e4 + 10;

vector <queue <int> > waves;

vector <ld> d(100);



struct ed{
    int fr, to;
    ld w;
};

vector <vector <ed>> G;

//map



void readG(){
    cin>>n>>m;
    G.resize(n);
    //cout<<"n m = "<<n<<' '<<m<<"\n";
    for (int i=0;i<m;++i){
        int a,b;
        ld w;
        cin>>a>>b>>w;
        a--; b--;
        w /= 1000.0;
        ed any = {a, b, w};
        G[a].push_back(any);
    }
    //cout<<"done\n";
}



void shG(){
    cout<<"G\n";
    for (int i=0;i<n;++i){
        cout<<i+1<<"\n";
        for (auto x: G[i]){
            cout<<x.to+1<<' '<<fixed<<x.w<<"\n";
        }
        cout<<"\n";
    }
}


void cvld(vector <ld> v){
    for (int i=0;i<v.size();++i)cout<<v[i]<<' ';
    cout<<"\n\n";
}



void fndWaves(int s){

    d.assign(n, inf);
    waves.resize(mx_way);
    d[s] = 0;
    waves[0].push(s);
    for (int l = 0; l < mx_way; ++l){
        //cout<<"l = "<<l<<"\n";
        while (!waves[l].empty()){
            int v = waves[l].front();
            waves[l].pop();
            //cout<<"l = "<<l<<"\n";
            //cout<<"v = "<<v+1<<"\n";
            for (ed e: G[v]){
                int nv = e.to;
                ld nl = d[v] + e.w;
                //cout<<"e = "<<e.fr+1<<' '<<e.to+1<<' '<<fixed<<e.w<<"\n";
                if (d[nv] > nl){
                    //if (d[e.to] != inf){
                    //    waves[l].erase(e.to);
                    //}
                    d[nv] = nl;
                    //cout<<"l e.w = "<<l<<' '<<e.w<<"\n";
                    //cout<<"d[e.to] = "<<d[e.to]<<"\n";
                    waves[(int)floor(nl)].push(e.to);
                }
            }
        }

    }
}


int main()
{
    ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cout.precision(5);
	readG();
	/*int fr; cin>>fr;
	fndWaves(fr);
	//shG();
	cout<<"dst\n";
	cvld(d);*/
	int k=1;
	cin>>k;
	for (int i=0;i<k;++i){
        int a,b; cin>>a>>b;
        a--; b--;
        fndWaves(a);
        //cout<<"d\n";
        //cvld(d);
        //cvld(d);
        if (d[b] == inf){
            cout<<-1<<"\n";
            continue;
        }
        ll ans = (ll)roundl(d[b] * 1000.0);
        //cout<<"ans = "<<ans<<"\n";
        //cout<<ans<<"\n";
        //cout<<d[b]<<' '<<ans<<"\n";
        cout<<ans<<"\n";
	}

}
/*
3 3
1 2 1001
2 3 1257
3 1 1782
10


5 5
1 2 2000
1 3 1000
1 4 1200
2 3 1500
3 4 1500



4
1 5
2 4
3 3
1 2

*/