#include <iostream>
#include <fstream>

#pragma GCC optimize("O5")

using namespace std;

int n = 0;
int k = 0;
int cnt = 0;

bool used[201];
int current[201];

void dfs(int i, int biggest, int c)
{
    if (i == n)
    {
        int mx = 0;
        int p = 0;

        for (int j = 0; j < n; j++)
        {
            if (current[j] > mx)
            {
                mx = current[j];
                p++;
            }
        }

        cnt += (p == k);
        return;
    }

    int b2 = biggest;
    if (c > k) {return;}
    if (n - i < k - c) {return;}

    for (int x = 1; x <= n; x++)
    {
        if (!used[x])
        {
            if (x > biggest) {c++;}
            biggest = max(biggest, x);
            used[x] = 1;
            current[i] = x;
            dfs(i + 1, biggest, c);
            used[x] = 0;
            biggest = b2;
            if (x > biggest) {c--;}
        }
    }
}

int main()
{
    ifstream fin("perm.in");
    ofstream fout("perm.out");

    fin >> n >> k;

    dfs(0, 0, 0);

    fout << cnt;
}