#include <stdio.h>
int main()
{
unsigned long a ,b;
while(scanf("%ld%ld",&a,&b)!=EOF)
{
printf("%ld\n",(a>b)?(a-b):(b-a));
}
return 0;
}
#include <stdio.h>
int main()
{
unsigned long a ,b;
while(scanf("%ld%ld",&a,&b)!=EOF)
{
printf("%ld\n",(a>b)?(a-b):(b-a));
}
return 0;
}