#include <iostream>
#include <iomanip>
#include <cstdio>
#include <queue>
#include <cstring>
#include <vector>
#include <map>
#include <algorithm>
#include <cctype>
#include <cmath>
#include <bitset>
#include <set>

using namespace std;

#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define RREP(i,n) for(int i=n-1;i>=0;i--)
#define FOR(i,k,n) for(int i=(k);i<(int)(n);i++)
#define all(i,n) (i),(i+n)

int dx4[4]={1,0,-1,0};
int dy4[4]={0,-1,0,1};
int dx8[8]={1,0,-1,1,-1,1,0,-1};
int dy8[8]={1,1,1,0,0,-1,-1,-1};

typedef pair<int, int> P;
typedef pair<string, int> SP;
typedef long long ll;
typedef pair<ll, ll> PLL;

const int INF = 1e9;
const ll LLINF = 1e18;
const int MAX_V = 1e6+1;
const ll mod = 1000000007;

// --------------------------------------
ll n;
vector<ll> divisor(ll n) {
  vector<ll> res;
  for(ll i=3; i*i<=n; i++) {
    if(n % i == 0) {
      res.push_back(i);
      if(i != n / i) res.push_back(n / i);
    }
  }
  return res;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  cin >> n;
  vector<ll> v = divisor(n);

  sort(v.begin(), v.end());
  if(v.size() > 0) cout << v[0] << endl;
  else cout << n << endl;
}