真实有效

#include<bits/stdc++.h>
using namespace std;
int main()
{
	int ikun,t,x,y;
	cin>>x>>y;
	t=(y-2*x)/2;
	ikun=x-t;
	if(t<0 or ikun<0)
	{
		cout<<"No";
		return 0;
	 } 
	if(ikun*2 + t*4 == y) cout<<"Yes";
	else cout<<"No";
	return 0;
        while(true)
}