krsu 3332

/*
* by: senb1
*/
#include <algorithm>
#include <iomanip>
#include <iostream>
#include <locale>
#include <numeric>
#include <cstring>
#include <cmath>

#include <deque>
#include <list>
#include <map>
#include <stack>
#include <string>
#include <vector>
#include <array>
#include <queue>
#include <set>

using namespace std;

#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define yes cout << "YES\n"
#define no cout << "NO\n"
#define fr first
#define sc second
#define endl "\n"
#define ll long long
#define ull unsigned long long
#define ld long double
#define nl cout << "\n";

const ll maxn = 1e6 + 10; // 1000000 + 10
const ll mod = 1000000000;
const int inf = 1000000000;
// 4294967296

ll binpow(ll a, ll b) {
    ll res = 1;
    while (b > 0) {
        if (b & 1)
            res = res * a % mod;
        a = a * a % mod;
        b >>= 1 % mod;
    }
    return res % mod;
}

ll divup(ll x, ll y) {
    return (x - 1) / y + 1;
}

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

ll lcm(ll a, ll b) {
    return (a * b) / gcd(a, b);
}

bool isPrime(int x) {
    if (x <= 1) return false;
    for (int i = 2; i <= sqrt(x) + 1; i++) {
        if (x % i == 0)
            return false;
    }
    return true;
}

int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    //cout << fixed << setprecision(12);
    //setlocale(LC_ALL, "RUS");

    int n;
    cin >> n;
    vector<pair<int,int> > v;
    for (int i = 1; i < n; i++) {
        for (int j = 1; j < sqrt(n); j++) {
            if (j * j * 20 + 30 * j * i > n)
                break;
            v.push_back(make_pair(i, j));
        }
    }

    int mx = 0;
    for (int i = 0; i < v.size(); i++) {
        mx = max(mx, v[i].fr * v[i].sc * v[i].sc);
    }

    /*
    for (auto x : v)
        cout << x.fr << ' ' << x.sc << endl;
    */
    cout << mx;
}