UvaOJ10055 hashmat the brave warrior

3WA。。。

/* UVa10055 Hashmat */
# include <stdio.h>
int main()
{
    unsigned long a, b;
while (scanf("%ld%ld", &a, &b) != EOF)
        printf("%ld\n", (a<b ? b-a:a-b));
return 0;
}