How to ignore negative numbers and terminate when a zero value is read?

Write a program that prompts the user for a collection of integers and displays the product of those integers. Your program should repeatedly prompt for, read data, ignore any negative numbers and terminate when a zero value is read.

when I enter number 0 the result is = 1 and when i enter negative number the result is = 1

Can someone tell me if my code is correct for ignore any negative numbers and terminate when a zero value is read.

#include <iostream>
using namespace std;
int main() {
int Num;
double product = 1.0;
int integerNumber=1;
int countNumber = 0;
cout << "Please enter the number of integer = ";
cin >> Num;
while (Num>countNumber)
{
    cout << "Please enter the integers = ";
    cin >> integerNumber;
    if (integerNumber == 0) {
        break;
    }
    else if (integerNumber >=  1) {
        product = product * integerNumber;
        countNumber = countNumber + 1;
    }
    else if (integerNumber <=-1)
    {
        integerNumber = integerNumber * -1;

    }
}
cout << " the product number of all integers is = " << product << endl;

system("pause");
return 0;

}