/*
********************************************
This code only for beginners.  Please, Don't Copy Past
********************************************
*/
 
#include<stdio.h>
#include<math.h>
#include<string.h>
#include<stdlib.h>
 
int main()
{
    int j=0,k=0;
    while(scanf("%d%d",&j, &k) !=EOF ){       
        j= j-k;
        if( j>=0)
            printf("%d\n",j);
        else
            printf("%d\n",j * (-1) );
    }
 
 return 0;
}