#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,a,b,c,d,e;
	cin>>n;
	a=n%10;
	b=n/10%10;
	c=n/100%10;
	d=n/1000;
	e=a*1000+b*100+c*10+d;
	if(n>e){
		cout<<n-e;
	}else{
		cout<<e-n;
	}
}
 
/**************************************************************
	Problem: 1702
	User: lvrenxiang
	Language: C++
	Result: Wrong Answer
****************************************************************/