#include <iostream>
using namespace std;

long long x, y;
bool dfs(int n, int s, int t) {
    if(n > 3) return false;
    if(s == x && t == y) return true;

    bool ret = false;

    for(int i=1;i<=2;i++) {
        int j = 3 - i;
        ret |= dfs(n+1, s-i, t-j) || dfs(n+1, s-i, t+j) || dfs(n+1, s+i, t-j) || dfs(n+1, s+i, t+j);
    }
    return ret;
}
int main() {
    cin >> x >> y;
    bool ans = dfs(0, 0, 0);
    if(ans)
        cout << "YES" << endl;
    else
        cout << "NO" << endl;
}