Counter problem

[SnugsCafe]

I need this program to display the number of vacation weeks based on the number of years an employee has been with a company. It needs to allow me to enter the number of years for as many employees as I like. I would also like it to calculate and display the total number of employees entered.
How do I make code for a counter? And how do I get the error message to work(b/c it's not working as far as I know)? I would really appreciate any advice or help.

#include <iostream>
using namespace std;

int main()
{
int years = 0;
int counter = 1;
int employees = 0;

cout << "Enter the years employed: ";
cin >> years;

while (years != -3)
{
{if (years == 0)
cout << "Vacation weeks: 0" << endl;
else if (years > 0 && years <= 5)
cout << "Vacation weeks: 1" << endl;
else if (years > 5 && years <= 10)
cout << "Vacation weeks: 2" << endl;
else if (years > 10)
cout << "Vacation weeks: 3" << endl;
else cout << "Invalid years" << endl;
}

cout << "Enter the years employed: ";
cin >> years;

}

return 0;
}

[Banfa]

a. initialise you counter variable to 0
b. at the start of the loop increment the counter

counter++;

c. After the loop has finished output the value of counter.

[SnugsCafe]

Thank you! :)