#include <bits/stdc++.h>
using namespace std;
signed main(){
	long long m,ans;
	cin>>ans>>m;
	if(m==0){
		m=1;
	}
	if(ans<0 && m%2==1){
		cout<<"YES"<<endl;
	}
	else if(ans>=0 || (ans<0 && m%2==0)){
		cout<<"NO"<<endl;
	}
	if(abs(ans)%2==0){
		cout<<"NO";
	}
	else{
		cout<<"YES";
	}
    return 0;
}
```cpp