#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> PII;
signed main() {
   ios::sync_with_stdio(false);
   cin.tie(nullptr);
   cout.tie(0);
   int n, m;
   cin >> n >> m;
   vector<PII> a(n);
   for (int i = 0; i < n; i++) {
      cin >> a[i].first;
      a[i].second = i;
   }
   vector<int> out(n);
   for (int i = 0; i < m; i++) {
      int x, y;
      cin >> x >> y;
      x--, y--;
      out[x]++;
      out[y]++;
   }
   sort(a.begin(), a.end());
   if (out[a[0].second] != 1) {
      cout << a[0].first << endl;
   } else {
      cout << a[1].first << endl;
   }
}