#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    ll n, s;
    cin >> n >> s;
    vector<ll> fact(s + 1);
    fact[0] = 1;
    for(int i = 1; i <= s; i++)fact[i] = i * fact[i - 1];
    vector<int> p(s), p2(s);
    function<void(int,int,ll)> dfs = [&](int i, int S, ll rem){
        if(i == s)return;
        ll v = 0;
        int cand = -1;
        for(int j = 0; j < s; j++){
            if(S >> j & 1)continue;
            if(rem >= fact[s - 1 - i]){
                rem -= fact[s - 1 - i];
                continue;
            }
            p[i] = j;
            dfs(i + 1, S | (1 << j), rem);
            break;
        }
    };
    dfs(0, 0, n);
    ll ans = 0;
    for(int i = 0; i < s; i++)p2[p[i]] = i;
    for(int i = 0, S = 0; i < s; i++){
        for(int j = 0; j < p2[i]; j++){
            if(S >> j & 1)continue;
            ans += fact[s - 1 - i];
        }
        S |= 1 << p2[i];
    }
    cout << ans << endl;
}