#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
#include <set>
#include <map>
using namespace std;

#define FOR(i,s,e) for(int i = (s);i <= (e);i++)

int N;
int M;

vector<int> edges[1010];

int a[1010];


int main()
{
    cin >> N >> M;

    FOR(i,1,N) cin >> a[i];

    int u,v;
    FOR(i,1,M)
    {
        cin >> u >> v;
        edges[u].push_back(v);
        edges[v].push_back(u);
    }

    FOR(i,1,N)
    {
        for(int j = 0;j < edges[i].size();j++)
        {
            for(int k = j + 1;k < edges[i].size();k++)
            {
                int arr[3];
                arr[0] = a[i];
                arr[1] = a[edges[i][j]];
                arr[2] = a[edges[i][k]];

                sort(arr,arr + 3);

                if(arr[0] != arr[1] && arr[1] != arr[2] && (arr[0] == a[i] || arr[2] == a[i]))
                {
                    cout << "YES" << endl;
                    return 0;
                }
            }
        }
    }

    cout << "NO" << endl;
    return 0;
}