Prime or Composite while

#include <iostream>
using namespace std;
int main(){
    int num2, two_numbers, input;
    cout << "Enter a Number: ";
    cin >> input;
    num2 = 1;
    if (input==0){
        cout << input << " is neither a prime number nor a composite number . . .";
    }
    else if (input!=0){
        while (num2<=input){
            //Reset to 0
            two_numbers=0;
            while (num2<=input){
                if (input%num2==0){
                    two_numbers++;
                }
                num2++;
            }
            if (two_numbers==2){
                cout << input << " is a prime number . . .";
            }
            else if (two_numbers!=2){
                cout << input << " is a composite number . . .";
            }
        }
    }
}