#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,b,c,d,e;
	cin>>a;
	b=a%10*1000;
	c=a/10%10*100;
	d=a/100%10*10;
	e=a/1000%10;
	b=b+c+d+e;
	a=a-b;
	cout<<a;
}
/**************************************************************
	Problem: 1702
	User: zengyixuan
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/