Uva 10055

#include <stdio.h>
#include <math.h>


int main()
{
  long int x1 = 0, x2 = 0, sum = 0;
  
  while (scanf("%ld %ld", &x1, &x2) != EOF)
  {
    sum = x1 - x2;
    printf("%ld\n", (long)fabs(sum));
  }


  return 0;
}