题解

#include <iostream>
using namespace std;
int main(){
int x,y,a=0;
cin>>x>>y;
switch(x){
case -1:
case 0:
case 1:a++;break;
}
switch(y){
case -1:
case 0:
case 1:a++;break;
}
if(a==2)cout<<"yes";
else cout<<"no";
return 0;
}