#include <stdio.h>

void main(void) {
	char str[1000] = "a";
	scanf("%s",str);
	int max = str[0] -'0';
	int min = str[0] -'0';
	for(int i = 1 ; i < 3 ; i++){
		if(str[i] -'0' > max){
			max = str[i] -'0';
		}else if(str[i] -'0' < min){
			min = str[i] -'0' ;
		}
	}
	printf("%d\n",max-min);
}