#include<bits/stdc++.h> 
using namespace std;
int main(){
	int x,y;
    cin>>x>>y;
    if(x>=-1&&x<=1&&y>=-1&&y<=1){
	    cout<<"yes";
    }else{
	    cout<<"no";
    }
}

//禁止复制 #include using namespace std; int main(){ int x,y; cin>>x>>y; if(x>=-1&&x<=1&&y>=-1&&y<=1){ cout<<"yes"; }else{ cout<<"no"; } }

#include<bits/stdc++.h> using namespace std; int main() { int a,b; cin>>a>>b; if(a>=-1&&a<=1&&b>=-1&&b<=1) cout<<"yes"; else cout<<"no"; return 0; }

*#include#include使用命名空间 std;int main（）{int a;辛>>A;if（sqrt（a）*sqrt（a）==a）{cout<<（sqrt）（a）;}else{cout<<“No，Chen”;}返回 0;

} *

#include #include #include using namespace std; int main(){ int w; cin>>w; if(sqrt(w)*sqrt(w)==w){ cout <<sqrt(w); }else{ cout <<"No,Chen"; }

return 0;

}

#include <iostream>
using namespace std;
int main(){
    int x,y;
    scanf("%d%d",&x,&y);
    if(x <= 1 && x >= -1 && y >= -1 && y <= 1)
        cout<<"yes"<<endl;
    else
        cout<<"no"<<endl;
    return 0;
}

#include<stdio.h> #include using namespace std; int main() { int a,b; cin>>a>>b; if((a0&&b1)||(a0&&b-1)||(a0&&b0)) { cout<<"yes"<<endl; }else if((a1&&b1)||(a1&&b-1)||(a1&&b0)) { cout<<"yes"<<endl; }else if((a==-1&&b1)||(a-1&&b==-1)||(a==-1&&b==0)) { cout<<"yes"<<endl; }else { cout<<"no"<<endl; } }

#include

using namespace std;

int main(){

int x,y;

cin>>x>>y;

if(x>=-1&&x<=1&&y>=-1&&y<=1){

	cout<<"yes";

}else{


	cout<<"no";

}

}

#include <queue>
#include <math.h>
#include <stack>
#include <stdio.h>
#include <iostream>
#include <vector>
#include <iomanip>
#include <string.h>
#include <algorithm>
using namespace std;
#define LL long long
const int N = 1e5 + 10;
const int INF = 0x3f3f3f3f;
int main()
{	
	int x,y;
	cin>>x>>y;
	if(x <= 1 && x >= -1 && y >= -1 && y <= 1)
	{
		cout <<"yes";
	}
	else 
	{
		cout <<"no";
	}
}