#include <iostream> #include <fstream> #include <cstdio> #include <cmath> #include <vector> #include <cstring> #include <string> #include <set> #include <map> #include <stack> #include <queue> #include <deque> #include <algorithm> using namespace std; #define REP(i,n) for(int i=0; i<n; ++i) #define FOR(i,a,b) for(int i=a; i<=b; ++i) #define FORR(i,a,b) for (int i=a; i>=b; --i) #define ALL(c) (c).begin(), (c).end() typedef long long ll; typedef vector<int> VI; typedef vector<ll> VL; typedef vector<VI> VVI; typedef vector<VL> VVL; typedef pair<int,int> P; typedef pair<ll,ll> PL; int main() { int n, m; cin >> n >> m; VI a(n); REP(i,n) cin >> a[i]; vector<P> e(m); REP(i,m){ cin >> e[i].first >> e[i].second; if (e[i].first > e[i].second) swap(e[i].first, e[i].second); e[i].first--; e[i].second--; } sort(ALL(e)); REP(j,m) REP(i,j){ if (e[i].second == e[j].first){ int p = e[i].first; int q = e[j].second; int r = e[i].second; if (a[p] != a[q] && (a[r] > max(a[p], a[q]) || a[r] < min(a[p], a[q]))){ cout << "YES" << endl; return 0; } } if (e[i].second == e[j].second){ int p = e[i].first; int q = e[j].first; int r = e[i].second; if (a[p] != a[q] && (a[r] > max(a[p], a[q]) || a[r] < min(a[p], a[q]))){ cout << "YES" << endl; return 0; } } if (e[i].first == e[j].first){ int p = e[i].second; int q = e[j].second; int r = e[i].first; if (a[p] != a[q] && (a[r] > max(a[p], a[q]) || a[r] < min(a[p], a[q]))){ cout << "YES" << endl; return 0; } } } cout << "NO" << endl; return 0; }