#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N;
    cin >> N;

    vector<ll> A(N);
    for (auto &x : A) cin >> x;

    for (int i = 0; i < N - 1; ++i) {
        int u, v;
        cin >> u >> v;
    }

    cout << *min_element(A.begin(), A.end()) << '\n';
}