#include <bits/stdc++.h>
#define mod 1000000007
using namespace std;
int main()
{
    int n, k, x;
    cin >> n >> k >> x;
    string str;
    for(int i = 1; i <= k; i++){
        str+= to_string(i);
    }
    int len = str.length();
    int cn = 0;
    do{
        cn++;
    }while(next_permutation(str.begin(), str.end()));
    cout << cn/2;
    return 0;
}