#include <bits/stdc++.h> 

using namespace std;

const int MAX_N = 300 + 5;
const int INF32 = 1e9;

int N, M, L, Q;
int d[MAX_N][MAX_N], f[MAX_N][MAX_N];

int main() {
    scanf("%d%d%d", &N, &M, &L);
    for (int i = 1; i <= N; i ++) {
        for (int j = 1; j <= N; j ++) {
            d[i][j] = INF32;
        }
        d[i][i] = 0;
    }
    for (int i = 1; i <= M; i ++) {
        int x, y, z;
        scanf("%d%d%d", &x, &y, &z);
        if (d[x][y] > z) {
            d[x][y] = z;
            d[y][x] = z;
        }
    }
    for (int k = 1; k <= N; k ++) {
        for (int i = 1; i <= N; i ++) {
            for (int j = 1; j <= N; j ++) {
                if (d[i][j] > d[i][k] + d[k][j]) {
                    d[i][j] = d[i][k] + d[k][j];
                }
            }
        }
    }
    for (int i = 1; i <= N; i ++) {
        for (int j = 1; j <= N; j ++) {
            f[i][j] = d[i][j] <= L ? 1 : INF32;
        }
        f[i][i] = 0;
    }
    for (int k = 1; k <= N; k ++) {
        for (int i = 1; i <= N; i ++) {
            for (int j = 1; j <= N; j ++) {
                if (f[i][j] > f[i][k] + f[k][j]) {
                    f[i][j] = f[i][k] + f[k][j];
                }
            }
        }
    }
    scanf("%d", &Q);
    for (int i = 1; i <= Q; i ++) {
        int x, y;
        scanf("%d%d", &x, &y);
        printf("%d\n", f[x][y] < N ? f[x][y] - 1 : -1);
    }
    return 0;
}