#include <iostream>

using namespace std;

bool search(int a, int b) ;

int main() {
    int a, b;
    
    cin >> a >> b;
    
    if(search(a, b))
        cout << "YES" << endl;
    else
        cout << "NO" << endl;

    return 0;
}

bool search(int a, int b) {
    if((a == 0) || (b == 0))
        return true;
    else if((a%2 != 0) && (b%2 != 0))
        return false;
    else if((a%2 == 0) && (b%2 == 0))
        if(search(a, b))
            return true;
    else
        if(search(a,b))
            return true;
}