#include <iostream>
using namespace std;
int main(){
    int a,b;cin>>a>>b;
    if(a>b){
        a^=b;
        b^=a;
        a^=b;
    }
    if((a%2 && b%2) || (b!=2 && a==1)){
        cout << "NO" << endl;
    }else{
        cout << "YES" << endl;
    }
}