#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define ALL(v) v.begin(), v.end()
typedef long long ll;

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

ll f(ll x){
  ll tmp=1;
  for(int i=2;i<=x;i++){
    tmp*=i;
  }
  return tmp;
}

int main(){
  ll n,s;
  cin>>n>>s;
  
  ll m=n;
  vector<ll> A(s+1);
  for(int i=s;i>0;i--){
    A[i]=m/f(i-1)+1;
    m-=m/f(i-1)*f(i-1);
  }
  
  vector<ll> B(s+1),C(s+1,1);
  for(int i=s;i>0;i--){
    int cnt=0;
    for(int j=1;j<=s;j++){
      if(C[j]==1) cnt++;
      if(A[i]==cnt){
        B[i]=j;
        C[j]=0;
        break;
      }
    }
  }
  
  vector<ll> D(s+1);
  for(int i=s;i>0;i--) D[B[i]]=s+1-i;
  
  ll ans=0;
  vector<ll> E(s+1,1);
  for(int i=1;i<=s;i++){
    ll cnt=0;
    for(int j=1;j<=D[i];j++){
      if(E[j]==1) cnt++;
    }
    ans+=f(s-i)*(cnt-1);
    E[D[i]]=0;
  }
  cout<<ans<<endl;
  
  return 0;
}