CBH TS10 Da Nang 2017-2018

#define task "CBH"

#include <iostream>
#include <cstdio>

using namespace std;

using ll = long long;
using ld = long double;

constexpr int N = 1e5 + 5;
ll x;

void Read()
{
    cin >> x;
}

void Solve()
{
    ll ans = 1;

    for (ll i = 1; i * i <= x; ++i)
        if (x % (i * i) == 0)
            ans = i;

    cout << ans;
}

int32_t main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if (fopen(task ".INP", "r"))
    {
        freopen(task ".INP", "r", stdin);
        freopen(task ".OUT", "w", stdout);
    }

    Read();
    Solve();
}