#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define ull unsigned long long
#define pii pair<int,int>
#define pll pair<long long, long long>
#define fi first
#define se second
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define TASKNAME "NAME"
void init()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
///freopen(TASKNAME".INP","r",stdin); freopen(TASKNAME".OUT","w",stdout);
}
const int SZ = 75;
const ll INF = INT_MAX / 2, MOD = 1e9+7, INFLL = 2e18;
const double epsilon = 1e-3;
int n,m,k,q;
struct Edge
{
int v;
ll w;
Edge(int _v = 0, ll _w = 0) : v(_v), w(_w) {}
};
vector<Edge> adj[SZ];
ll d[SZ][SZ][SZ], len[SZ][SZ];
bool vis[SZ][SZ];
void dijkstra(int s)
{
for(int i = 1; i <= n; i++)
{
for(int j = 0; j <= min(k,n); j++)
{
d[s][i][j] = INFLL;
}
}
d[s][s][0] = 0;
for(int i = 1; i <= min(k,n); i++)
{
for(int u = 1; u <= n; u++)
{
for(Edge e : adj[u])
{
int v = e.v;
ll w = e.w;
d[s][v][i] = min(d[s][v][i], d[s][u][i-1] + w);
}
}
}
}
int main()
{
init();
cin >> n >> m;
memset(len, -1, sizeof(len));
for(int i = 1; i <= m; i++)
{
int u,v;
ll w;
cin >> u >> v >> w;
if(len[u][v] == -1 || w < len[u][v]) len[u][v] = w;
}
for(int i = 1; i <= n; i++)
{
for(int j = 1; j <= n; j++)
{
if(i == j || len[i][j] == -1) continue;
adj[i].pb({j, len[i][j]});
}
}
cin >> k >> q;
for(int u = 1; u <= n; u++)
{
dijkstra(u);
}
while(q--)
{
int u,v;
cin >> u >> v;
ll res = INFLL;
for(int i = 0; i <= min(k,n); i++)
{
res = min(res, d[u][v][i]);
}
cout << (res == INFLL ? -1 : res) << '\n';
}
}
