#include <bits/stdc++.h>

using i64 = long long;

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    int n, m;
    std::cin >> n >> m;
    
    std::vector<int> a(m), b(m), c(m);
    for (int i = 0; i < m; i++) {
        std::cin >> a[i] >> b[i] >> c[i];
        a[i]--, b[i]--;
    }
    
    int q;
    std::cin >> q;
    
    std::vector<int> u(q), v(q);
    for (int i = 0; i < q; i++) {
        std::cin >> u[i] >> v[i];
        u[i]--, v[i]--;
    }
    
    std::vector<int> f(n);
    std::iota(f.begin(), f.end(), 0);
    auto find = [&](int x) {
        while (f[x] != x) {
            x = f[x] = f[f[x]];
        }
        return x;
    };
    auto merge = [&](int x, int y) -> bool {
        x = find(x);
        y = find(y);
        if (x == y) {
            return false;
        }
        f[y] = x;
        return true;
    };
    
    int ans = 1E9;
    
    std::vector<int> p(m);
    std::iota(p.begin(), p.end(), 0);
    std::sort(p.begin(), p.end(),
        [&](int i, int j) {
            return c[i] < c[j];
        });
    for (int i = 0; i < q; i++) {
        merge(a[u[i]], b[u[i]]);
        merge(a[v[i]], b[v[i]]);
    }
    std::vector<bool> use(m);
    int tot = 0;
    for (auto j : p) {
        if (merge(a[j], b[j])) {
            tot += c[j];
            use[j] = true;
        }
    }
    for (int i = 0; i < n; i++) {
        if (find(i) != find(0)) {
            std::cout << -1 << "\n";
            return 0;
        }
    }
    std::iota(f.begin(), f.end(), 0);
    for (auto j : p) {
        if (use[j]) {
            merge(a[j], b[j]);
        }
    }
    
    std::vector<int> id(n, -1);
    int cnt = 0;
    for (int i = 0; i < n; i++) {
        if (id[find(i)] == -1) {
            id[find(i)] = cnt++;
        }
        id[i] = id[find(i)];
    }
    
    f.resize(cnt);
    std::iota(f.begin(), f.end(), 0);
    std::vector<int> r;
    for (int i = 0; i < m; i++) {
        int j = p[i];
        if (merge(id[a[j]], id[b[j]])) {
            r.push_back(j);
        }
    }
    use.assign(m, false);
    for (int mask = 0; mask < (1 << q); mask++) {
        int res = tot;
        std::iota(f.begin(), f.end(), 0);
        for (int i = 0; i < q; i++) {
            int j;
            if (mask >> i & 1) {
                j = u[i];
            } else {
                j = v[i];
            }
            if (!use[j]) {
                use[j] = true;
                merge(id[a[j]], id[b[j]]);
                res += c[j];
            }
        }
        for (auto j : r) {
            if (merge(id[a[j]], id[b[j]])) {
                res += c[j];
            }
        }
        
        for (int i = 0; i < q; i++) {
            int j;
            if (mask >> i & 1) {
                j = u[i];
            } else {
                j = v[i];
            }
            use[j] = false;
        }
        ans = std::min(ans, res);
    }
    
    std::cout << ans << "\n";
    
    return 0;
}