#include<stdio.h>

int main(void)
{
	int n,m;
    
    
    scanf("%d%d",&n,&m);
    
    if(n < 2 || n > pow(10,5)) printf("-1\n");
    if(m < 2 || m > 50) 	   printf("-1\n");
    
    if(n <= m ){
        printf("1\n");
    }else{
        printf("-1\n");
    }
    
}