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