#include <bits/stdc++.h>
using namespace std;
int main(){
	
	int x,y,n,i,c;
	cin>>x>>y>>n;
	i=x+y;
	c=n-i;
	cout<<c;
	
	return 0;
}
/**************************************************************
	Problem: 1597
	User: huangyaojie3
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/