#include <bits/stdc++.h>
using namespace std;
using lli = int_fast64_t;
using ulli = uint_fast64_t;
#define debug(x) cerr << #x << " : " << x << endl
#define debugv(x) cerr << #x << " : {";for(auto value_of_x:x){ cerr << value_of_x << ", ";}cerr << endl
#define debugst(x) auto xt = x;cerr << #x << " : {";for(int i=0;i<x.size();i++){ cerr << xt.top() << ", ";xt.pop();}cerr << endl
#define debugvp(x) cerr << #x << " : {";for(auto value_of_x:x){ cerr << value_of_x.first << " : " << value_of_x.second << ", ";}cerr << endl
template<typename T>
T ncr(T left, T right) {
	right = min(left - right, right);
	T ans = 1;
	for (T i = 1; i <= right; i++) {
		ans = ans * (left - right + i) / i;
	}
	return ans;
}

const lli MOD = 1000000007;
const lli LIMIT = 1000000000000000000 * 5;
const int tenfive = 100000;

int main() {
	int L, R, M;
	cin >> L >> R >> M;
	int c = R - L + 1;
	cout << min(c,M) << endl;
	return 0;
}