// #include <bits/stdc++.h>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <map>
#include <unordered_map>
#include <vector>
#include <iomanip>
#include <string>
#include <queue>
#include <set>
#include <deque>
using namespace std;
#define int long long
#define endl "\n"
#define fi first
#define se second
const int M=1e9+7;
const int inf = 1e14;
const int LOG=18;
const int N=7e1+5;
int n , m , c , w , k , t=1 , q=1 , x , y , z , l , r;
int dp[N][N][N];
vector<pair<int,int>>a[N];
void solve(){
cin >> n >> m;
for (int i=1;i<=n;i++){
for (int j=1;j<=n;j++){
for (int k=0;k<=n;k++){
dp[i][j][k]=inf;
if (i==j)dp[i][j][k]=0;
}
}
}
for (int i=0;i<m;i++){
cin >> x >> y >> z;
if (dp[x][y][1]<z)continue;
dp[x][y][1]=z;
}
for (int i=1;i<=n;i++){
for (int j=1;j<=n;j++){
if (!dp[i][j][1] or dp[i][j][1]==inf)continue;
a[i].push_back({j,dp[i][j][1]});
}
}
for (int i=1;i<=n;i++){
for (int j=1;j<=n;j++){
for (int k=0;k<=n-1;k++){
for (auto [l,w]:a[j]){
dp[i][l][k+1]=min(dp[i][l][k+1],dp[i][l][k]);
dp[i][l][k+1]=min(dp[i][l][k+1],dp[i][j][k]+w);
}
}
}
}
cin >> k >> q;
k=min(k,n);
for (int i=0;i<q;i++){
cin >> x >> y;
if (dp[x][y][k]==inf){
cout << -1 << endl;
continue;
}
cout << dp[x][y][k] << endl;
}
}
signed main()
{
// ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE
// cin.tie(0), cout.tie(0);//DO NOT USE IN INTERACTIVE
cout << fixed << setprecision(9);
srand(time(0));
// int t=1;
// cin >> t;
for (int _=1;_<=t;_++){
solve();
q++;
}
}
