#include <bits/stdc++.h>
using namespace std;

int main() {
    int m,n;
    while(cin>>m>>n){
        if (n==1) cout<<"YES"<<endl;
        else{
            if ((m%2)!=(n%2))  cout<<"YES"<<endl;
            else cout<<"NO"<<endl;
        

        }

    }
}