#include <iostream>
using namespace std;

int main() {
    int n,m,k;
    cin >> n >> m >> k;
    int arr[n] = {0,};

    int t = 0;
    for (int i = 0;i < m;i++) {
        int s = 0;
        for (int j = 1;j <= i+1;j++) {
            if ((i+1) % 2 == 0) {
                s++;
            }
        }
        if (s == 2) {
            arr[t]++;
        }
        s = 0;
        t++;
    }
    cout << arr[k];
    return 0;
}