#include <bits/stdc++.h>
using namespace std;
int main(){
	int a,b,n,c; 
	cin>> a >> b >> n ;
	c=a+b;
    cout<<n-c*0.9; 
	return 0;	
}
/**************************************************************
	Problem: 1598
	User: chenjiahui
	Language: C
	Result: Compile Error
****************************************************************/