#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
void solve(){
  int n, m;
  cin >> n >> m;
  vector<vector<int> > v(n + 2);
  vector<int> a(n + 2);
  for(int i = 1; i <= n; ++i){
    cin >> a[i];
  }
  for(int i = 1; i <= m; ++i){
    int u, w;
    cin >> u >> w;
    v[u].push_back(w);
    v[w].push_back(u);
  }
  if(n == 1){
    cout << a[1] << '\n';
    return;
  }
  int ans = 0;
  int miny = 0x7fffffff;
  vector<bool> isval(n + 2);
  auto dfs = [&](int pos, auto&& self) -> void {
    if(isval[pos])
      return;
    isval[pos] = 1;
    if(v[pos].size() >= 2){
      ans = max(ans, a[pos]);
    }
    else{
      miny = min(miny, a[pos]);
    }
    for(int i: v[pos]){
      self(i, self);
    }
  };
  dfs(1, dfs);
  if(miny = 0x7fffffff){
    cout << ans << '\n';
  }
  else{
    cout << max(miny, ans) << '\n';
  }
}

int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int t = 1;
  // cin >> t;
  while(t--){
    solve();
  }
}