#define _USE_MATH_DEFINES
#include<stdio.h>
#include<string>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<vector>
#include<stack>
#include<queue>
#include <algorithm>
#include<math.h>
#include<set>
#include<map>
#include<iomanip>

//#include<bits/stdc++.h>



using namespace std;




int main() {
	
	int x,y,d;
	cin>>x>>y>>d;
	long long int p=0;
	for(int i=0;i<=x;i++){
		if(d-i>y)continue;
		if(d-i<0)break;
		p++;
	}
	cout<<p<<endl;

	return 0;
}