#include <bits/stdc++.h>
using namespace std;
int main(){
	int a,k,l,d,j;
	cin>>a;
	k=a%10;
	l=a/10%10;
	d=a/100;
	if(k<l){
		swap(k,l);
	}
	if(k<d){
		swap(k,d);
	}
	if(l>d){
		swap(l,d);
	}j=k-l;
	cout<<j;
}

/**************************************************************
	Problem: 1667
	User: tonghuawei
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/