#include<iostream>
 
using std :: cout;
using std :: cin;
using std :: endl;
 
int main()
{
   long long int a = 0, bigPrime = 0, smallPrime = 2, prime = 0;
   cout << "Please enter a number...!" << endl;
   cin >> a;
 
   for (long long int i = 2; i * i <= a; i++) {
       if (a % i == 0) {
           a /= i;
           i--; // this is to handle repeated factors
       }
   }
 
   cout << "The biggest prime factor is = " << a << endl;
   return 0;
}

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