#include<bits/stdc++.h>
using namespace std;
using Int = long long;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}


struct Precision{
  Precision(){
    cout<<fixed<<setprecision(12);
  }
}precision_beet;

//INSERT ABOVE HERE
signed main(){
  int n;
  cin>>n;
  double ans=12;
  for(int i=0;i<5;i++){
    ans*=n-i;
    ans/=99-i;
  }
  cout<<ans<<endl;
  return 0;
}