题目链接:http://codeforces.com/contest/731/problem/B
#include<bits/stdc++.h>
#define MX 200007
using namespace std;
int ar[MX];
int main()
{
bool flag=1;
int n;
cin>>n;
for(int i = 1;i<=n;i++) cin>>ar[i];
for(int i =0;i<=n;i++)
{
if( ar[i]%2 )
{
if(ar[i+1]==0) {flag=0; break;}
else ar[i+1]--;
}
}
if(flag) puts("YES");
else puts("NO");
return 0;
}