#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>
#include <set>

using namespace std;
using ll=long long;

int main(){
    ll n,s,ans=0;
    cin>>n>>s;
    vector<ll> f(s,1);
    priority_queue<ll,vector<ll>,greater<ll>> q;
    vector<pair<ll,ll>> revperm;

    for(ll i=1;i<s;i++) f[i]=i*f[i-1];
    for(ll i=1;i<=s;i++) q.push(i);
    for(ll i=s-1;i>=0;i--){
        ll p=n/f[i];
        n-=p*f[i];
        vector<ll> v;
        while(v.size()<=p){
            v.push_back(q.top());
            q.pop();
        }
        revperm.push_back(make_pair(v.back(),s-1-i+1));
        for(ll i=0;i<v.size()-1;i++) q.push(v[i]);
    }
    sort(revperm.begin(),revperm.end());
    set<ll> used;
    for(ll i=0;i<s;i++){
        ll revi=revperm[i].second;
        ll cnt=0;
        for(ll j=1;j<revi;j++){
            if(!used.count(j)) cnt++;
        }
        ans+=f[s-i-1]*cnt;
        used.insert(revi);
    }
    cout<<ans<<endl;
    return 0;
}