#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: huanglingkai
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/