#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
#include <fstream>
#include <utility>
#include <functional>
#include <time.h>
#include <stack>
#include <array>
#include <list>
#define popcount __builtin_popcount
using namespace std;
typedef long long ll;
typedef pair<int, int> P;
vector<int> getperm(int n, ll ind){
    vector<int> res(n);
    bool used[22]={};
    ll f[22];
    f[0]=1;
    for(int i=1; i<=n; i++) f[i]=f[i-1]*i;
    for(int i=0; i<n; i++){
        int c=ind/f[n-1-i];
        ind%=f[n-1-i];
        int cnt=0;
        for(int j=0; j<n; j++){
            if(used[j]) continue;
            if(c==cnt){
                res[i]=j;
                used[j]=1;
                break;
            }
            cnt++;
        }
    }
    return res;
}
ll getind(int n, vector<int> p){
    ll f[22];
    f[0]=1;
    for(int i=1; i<=n; i++) f[i]=f[i-1]*i;
    ll ind=0;
    bool used[22]={};
    for(int i=0; i<n; i++){
        int c=0;
        for(int j=0; j<n; j++){
            if(used[j]) continue;
            if(j==p[i]){
                ind+=c*f[n-1-i];
                used[j]=1;
                break;
            }
            c++;
        }
    }
    return ind;
}
int main()
{
    ll n; int s;
    cin>>n>>s;
    vector<int> p=getperm(s, n);
    vector<int> q(s);
    for(int i=0; i<s; i++) q[p[i]]=i;
    cout<<getind(s, q)<<endl;
    return 0;
}