#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;
using ll = long long ;
using P = pair<int,int> ;
using pll = pair<long long,long long>;
constexpr int INF = 1e9;
constexpr long long LINF = 1e17;
constexpr int MOD = 1000000007;
int n = 1005,m;
vector<vector<int>> graph(n,vector<int>());
vector<int> a(n);

bool iskadomatu(vector<int> v){
    if(v[0] == v[1] || v[1] == v[2] || v[0] == v[2]) return false;
    if(v[1] > v[0] && v[1] > v[2]) return true;
    if(v[1] < v[0] && v[1] < v[2]) return true;
    return false;
}

bool dfs(int i,vector<int> v,int p=-1){
    if((int)(v.size()) == 3){
        if(iskadomatu(v)) return true;
        else return false;
    }

    bool res = false;
    for(int c:graph[i]){
        if(c==p) continue;
        v.push_back(a[c]);
        res = res || dfs(c,v,i);
        v.pop_back();
    }

    return res;
}

int main(){
    cin >> n >> m;
    rep(i,n) cin >> a[i];
    rep(i,m){
        int u,v;
        cin >> u >> v;
        --u;--v;
        graph[u].push_back(v);
        graph[v].push_back(u);
    }

    vector<int> v;
    rep(i,n){
        v.push_back(a[i]);
        if(dfs(i,v)){
            cout << "YES" << endl;
            return 0;
        }
        v.pop_back();
    }
    cout << "NO" << endl;
    return 0;
}