#include <iostream>
#include <cstring>
#include <queue>
#include <map>
#include <cstdio>
#include <unordered_map>
#include <deque>
#include <iomanip>
#include <cmath>
#include <vector>
#include <algorithm>
#include <stack>
#include <set>
#include <array>
#include <bitset>
#include <limits.h>
#include <numeric>
#define x first
#define y second

using namespace std;
typedef  long long LL;
typedef long long ll  ; 
typedef pair<int,int> PII;
typedef pair<int,LL> PIL;
typedef pair<int ,PII> PIII ;
typedef pair<int, pair<PII ,int > > PIIII;
typedef pair<LL , LL> PLL ; 
typedef pair<LL ,int > PLI ;
typedef pair<int,char > PIC ; 
typedef unsigned long long ULL ;
 
const int N = 5e5+10,M = 4e5+10  ;
const LL mod = 1e9+7 , INF = 1e18+10;
const int inf =  1e8 ; 
const double eps = 1e-7 ;
const ULL  P=  131 ;
LL n , m  , k   ;



void solve( ) {
	cin >> n >> m ;
	vector<int> a(n) ;
	for(auto &x : a ) cin >> x ;
	while( m -- ) {
		int u , v;  cin >> u >> v ;
	}
	
	if( n == 1 ) {
		cout << a[0] << '\n'; return ;
	}
	sort( a.begin() , a.end()) ; reverse( a.begin() , a.end()) ;
	if( a[0] == a[1] ) cout << a[0] ;
	else cout << a[1] << '\n';
	
	
} 	
 
 
 
int main(){ 	
	ios::sync_with_stdio(false);
	cin.tie( 0 ) ; cout.tie(0) ;
	int T = 1 ;
	// cin >> T ;
	while(T-- ){	
		solve() ;  
   	}        
 	return  0 ;
}