最大质因子

#include <iostream>

using namespace std;
#define ll long long

ll get_max_prime(ll n){
    ll cmp = 0;
    for(ll i = 2; i <= n; i++){
        while(n % i == 0){
            n /= i;
            cmp = i;
        }
    }
    if(n > 1 && n > cmp)
        cmp = n;
    return cmp;
}
int main()
{
    ll n;
    while(cin >> n){
        cout << get_max_prime(n) << endl;
    }
    return 0;
}