#include <bits/stdc++.h>

#ifdef DEBUG
#include <Mylib/Debug/debug.cpp>
#else
#define dump(...) ((void)0)
#endif

template <typename T, typename U>
bool chmin(T &a, const U &b){
  return (a > b ? a = b, true : false);
}

template <typename T, typename U>
bool chmax(T &a, const U &b){
  return (a < b ? a = b, true : false);
}

template <typename T, size_t N, typename U>
void fill_array(T (&a)[N], const U &v){
  std::fill((U*)a, (U*)(a + N), v);
}

template <typename T, size_t N, size_t I = N>
auto make_vector(const std::array<int, N> &a, T value = T()){
  static_assert(I >= 1);
  static_assert(N >= 1);
  if constexpr (I == 1){
    return std::vector<T>(a[N - I], value);
  }else{
    return std::vector(a[N - I], make_vector<T, N, I - 1>(a, value));
  }
}

template <typename T>
std::ostream& operator<<(std::ostream &s, const std::vector<T> &a){
  for(auto it = a.begin(); it != a.end(); ++it){
    if(it != a.begin()) s << " ";
    s << *it;
  }
  return s;
}

template <typename T>
std::istream& operator>>(std::istream &s, std::vector<T> &a){
  for(auto &x : a) s >> x;
  return s;
}

std::string YesNo(bool value){return value ? "Yes" : "No";}
std::string YESNO(bool value){return value ? "YES" : "NO";}
std::string yesno(bool value){return value ? "yes" : "no";}

template <typename T>
void putl(const T &value){
  std::cout << value << "\n";
}

template <typename Head, typename ... Tail>
void putl(const Head head, const Tail &... tail){
  std::cout << head << " ";
  putl(tail ...);
}

namespace haar_lib {
  std::vector<int> index_to_permutation(int64_t N, int S){
    std::vector<int> ret;
    std::vector<int> nums(S);
    std::iota(nums.begin(), nums.end(), 0);

    int64_t p = 1;
    for(int i = 1; i <= S; ++i) p *= i;

    for(int i = 0; i < S; ++i){
      p /= S - i;
      int64_t index = N / p;

      for(int j = 0, k = -1; j < S; ++j){
        if(nums[j] >= 0){
          ++k;
          if(k == index){
            ret.push_back(j);
            nums[j] = -1;
            break;
          }
        }
      }

      N %= p;
    }

    return ret;
  }

  int64_t permutation_to_index(const std::vector<int> &a){
    const int N = a.size();
    int64_t ret = 0;
    std::vector<int> nums(N);
    std::iota(nums.begin(), nums.end(), 0);

    int64_t p = 1;
    for(int i = 1; i <= N; ++i) p *= i;

    for(int i = 0; i < N; ++i){
      p /= N - i;

      for(int j = 0, k = -1; j < N; ++j){
        if(nums[j] >= 0){
          ++k;

          if(nums[j] == a[i]){
            ret += p * k;
            nums[j] = -1;
            break;
          }
        }
      }
    }

    return ret;
  }

  std::vector<int> inverse_permutation(const std::vector<int> &a){
    const int N = a.size();
    std::vector<int> ret(N);
    for(int i = 0; i < N; ++i){
      ret[a[i]] = i;
    }

    return ret;
  }
}


namespace solver {
  using namespace haar_lib;

  constexpr int m1000000007 = 1000000007;
  constexpr int m998244353 = 998244353;

  void init(){
    std::cin.tie(0);
    std::ios::sync_with_stdio(false);
    std::cout << std::fixed << std::setprecision(12);
    std::cerr << std::fixed << std::setprecision(12);
    std::cin.exceptions(std::ios_base::failbit);
  }

  void solve(){
    int64_t N, S; std::cin >> N >> S;

    auto p = index_to_permutation(N, S);
    p = inverse_permutation(p);
    int64_t ans = permutation_to_index(p);

    std::cout << ans << "\n";
  }
}

int main(){
  solver::init();
  while(true){
    try{
      solver::solve();
      std::cout << std::flush;
      std::cerr << std::flush;
    }catch(const std::istream::failure &e){
      break;
    }catch(...){
      break;
    }
  }
  return 0;
}