题解

#include<iostream>
using namespace std;
int main(){
    int a,b;
    cin>>a>>b;
    if((a==1&&b==-1)||(a==1&&b==1)||(a==-1&&b==-1)||(a==-1&&b==1)||(a==0&&b==0)){
        cout<<"yes";
    }else{
        cout<<"no";
    }
    return 0;
}