#include<bits/stdc++.h> 
using namespace std;
int x,y,n,l=0;
int main() 
    cin>>x>>y>>n;
    l=n-(x+y);	
    printf(%d,l);
}
/**************************************************************
	Problem: 1597
	User: chenyichuen
	Language: C++
	Result: Compile Error
****************************************************************/