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

int main() {
    int a, b;
    cin >> a >> b;

   
    if ((a > 0 && b > 0) || (a < 0 && b < 0)) {
        cout << "YES" << endl;
    } else {
        cout << "NO" << endl;
    }

    return 0;
}