#include<bits/stdc++.h>
#define R(n) for(I i=0;i<(n);i++)
using std::cin;
using I=long long;

I v[1<<18],A[1<<18]={},s[1<<18]={},n,q,y=1,a,b;
I r(I a){return v[a]-a?v[a]=r(v[a]):a;}

int main(){
	cin>>n>>q;
	R(n){cin>>A[i];if(i&1)A[i]*=-1;}
	n++;R(n){A[n-i]-=A[n-i-1];v[i]=i;}
	R(q){cin>>a>>b;v[r(--a)]=r(b);}
	R(n)s[r(i)]+=A[i];
	R(n)if(s[i])y=0;
	printf(y?"YES\n":"NO\n");
	return 0;
}