#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define int long long
typedef long long ll;
typedef pair<int, int> PII;
const int N = 2e5+7;
int n, m, k;
int a[N];

void sovle()
{
    cin>>n>>m;
    vector<int>v[n+5];
    for(int i=1;i<=n;i++) cin>>a[i];
    for(int i=1;i<=m;i++){
        int x,y;
        cin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int max1=0;
    for(int i=1;i<=n;i++){
        if(v[i].size()>=2) max1=max(max1,a[i]);
        else continue;
        int min1=2e12;
        for(auto ed:v[i]){
            min1=min(min1,a[ed]);
        }
        max1=max(max1,min1);
    }
    if(n==1) cout<<a[1];
    else cout<<max1<<endl;
}

signed main()
{
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    int ING = 1;
    //cin>>ING;
    while (ING--)
    {
        sovle();
    }
    
    return 0;
}