fint

#include <iostream>
#include <vector>

const int INF = 1000000000;

int main() {
    int n;
    std::cin >> n;
    std::vector<int> weigths(n);
    for (int i = 0; i < n; i++) {
        std::cin >> weigths[i];
    }
    std::vector<std::vector<std::pair<int, int>>> g(n);

    int m;
    std::cin >> m;

    for (int i = 0; i < m; i++) {
        int a, b;
        std::cin >> a >> b;
        a--;
        b--;
        g[a].push_back({b, weigths[b]});
        g[b].push_back({a, weigths[a]});
    }

    int s = 0;

    std::vector<int> d(n, INF), p(n);
    d[s] = 0;
    std::vector<char> u(n);
    for (int i = 0; i < n; ++i) {
        int v = -1;
        for (int j = 0; j < n; ++j)
            if (!u[j] && (v == -1 || d[j] < d[v]))
                v = j;
        if (d[v] == INF)
            break;
        u[v] = true;

        for (size_t j = 0; j < g[v].size(); ++j) {
            int to = g[v][j].first,
                    len = g[v][j].second;
            if (d[v] + len < d[to]) {
                d[to] = d[v] + len;
                p[to] = v;
            }
        }
    }

    if (d[n - 1] == INF) {
        std::cout << -1;
    } else {
        std::cout << d[n - 1];
    }
}