#include "bits/stdc++.h"
#define _CRT_SECURE_NO_WARNINGS
#define rep(i,n) for(int i = 0;i < n;i++)
#define REP(i,n,k) for(int i = n;i < k;i++)
#define P(p) cout << (p) << endl;
#define sP(p) cout << setprecision(15) << fixed << p << endl;
#define Pi pair<int,int>
#define IINF 1e9
#define LINF 1e18
#define vi vector<int>
#define mp make_pair
#define pb push_back

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
int dx[] = { 0, 1, 0, -1 };
int dy[] = { -1, 0, 1, 0 };

unsigned long long sttoi(std::string str) {
	unsigned long long ret;
	std::stringstream ss; ss << str;
	ss >> ret;
	return ret;
}

ull gcd(ull a, ull b) {
	if (b > a)swap(a, b);
	if (b == 0) return a;
	return gcd(b, a%b);
}

void solve() {
	int n;
	cin >> n;
	double numer = 1, denom = 1;
	for (int i = 0; i < 5; i++) {
		numer *= n - i;
		numer /= i + 1;
	}
	for (int i = 0; i < 5; i++) {
		denom *= 99 - i;
		denom /= i + 1;
	}
	sP((numer / denom) * 12);
}	

int main() {
	solve();
	return 0;
}