#include <iostream>
using namespace std;
int main()
{
    long long n, m, k;
    cin >> n, m, k;
    if (n == 0 || k == 0 || (n == 0 && k == 0))
    {
        cout << 0;
    }

    else if (n > 0 && k > 0)
    {
        if (n != 0 && (n >= (2 * k))) cout << k;
        if (n != 0 && (n >= (2 * k)) && m >= k) cout << k;
        if (n == m == k != 0) cout << k;
    }

    return 0;
}