#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;
}
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