#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
using namespace std;

using ll = long long;
using P = pair<int, int>;
constexpr int INF = 1001001001;
constexpr int mod = 1000000007;
// constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    uint64_t N, S;
    cin >> N >> S;
    vector<uint64_t> fact(S, 1);
    for(int i = 1; i < S; ++i)  fact[i] = fact[i - 1] * i;
    
    vector<int> nums, perm;
    for(int i = 1; i <= S; ++i) nums.emplace_back(i);
    int j;
    while((j = perm.size()) < S){
        int k = 0;
        while(N >= fact[S - j - 1]){
            N -= fact[S - j - 1];
            k += 1;
        }
        perm.emplace_back(nums[k]);
        nums.erase(nums.begin() + k);
    }
    
    vector<int> inv(S);
    for(int i = 0; i < S; ++i){
        inv[perm[i] - 1] = i + 1;
    }
    
    for(int i = 1; i <= S; ++i) nums.emplace_back(i);
    uint64_t ans = 0;
    for(int i = 0; i < S; ++i){
        int j = lower_bound(begin(nums), end(nums), inv[i]) - begin(nums);
        ans += fact[S - i - 1] * j;
        nums.erase(nums.begin() + j);
        
    }
    
    cout << ans << endl;

    return 0;
}