So recently i made this code for my homework:

Code:
#include <iostream>
using namespace std;
int main()

{
   int date;
   int month;
   char ans;
   cout<<"Enter your birth month and date to determine your zodiac sign\n\n"<<endl;

    while (!((ans=='n') || (ans=='N')))
    {
    cout<<"Enter your birth month:";
    cin>>month;
    cout<<"Enter your birth date:";
    cin>>date; 
   
    
    if (( month == 1 && date >= 20 && date <= 31 ) || ( month == 2 && date <=18 ))
    {
         cout<<"Your zodiac sign is AQUARIUS\n\n";
         cout<<"Aquarius is an old constellation. As the Water Carrier or Water Bearer,\nhe is carved in stones";
         cout<<"of the Babylonian Empire and probably is still older than that period.\n";
         
    }
    else if (( month == 2 && date >= 19 && date <= 28) || ( month == 3 && date <= 20))
    {
         cout<<"Your zodiac sign is PISCES\n\n";
         cout<<"Pisces was named after Aphrodite and Eros.The story of Pisces originated from\n";
         cout<<"the destructive monster, Typhon.\n";
    }
    else if (( month == 3 && date >= 21 && date <= 31) || ( month == 4 && date <= 19))
    {
         cout<<"Your zodiac sign is ARIES\n\n";
         cout<<"Aries is a zodiacal constellation representing the ram of the Golden\n";
         cout<<"Fleece sought by Jason and the Argonauts.\n";
         
    }
    else if (( month == 4 && date >= 20 && date <= 30 )  || ( month == 5 && date <= 20))
    {
         cout<<" Your zodiac sign is TAURUS\n";
    }
    else if (( month == 5 && date >= 21 && date <= 31 )  || ( month == 6 && date <= 20 ))
    {
         cout<<" Your zodiac sign is GEMINI\n";
    }
    else if (( month == 6 && date >= 21 && date <= 30 ) || ( month == 7 && date <= 22 ))
    {
         cout<<" Your zodiac sign is CANCER\n";
    }
    else if (( month == 7 && date <= 23 && date <= 31) || ( month == 8 && date <= 22))
    {
         cout<<" Your zodiac sign is LEO\n";
    }
    else if (( month == 8 && date >= 23 && date <= 31) || ( month == 9 && date <= 22 ))
    {
         cout<<" Your zodiac sign is VIRGO\n";
    }
    else if (( month == 9 && date >= 23 && date <= 30) || ( month == 10 && date <= 22))
    {
         cout<<" Your zodiac sign is LIBRA\n";
    }
    else if (( month == 10 && date >= 23 && date <= 31 ) || ( month == 11 && date <= 21))
    {
         cout<<" Your zodiac sign is SCORPIO\n";
    }
    else if (( month == 11 && date >= 22 && date <= 30 ) || ( month == 12 && date <= 21))
    {
         cout<<" Your zodiac sign is SAGUITTARIUS\n";
    }
    else if (( month == 12 && date >= 22 && date <= 31 ) || ( month == 1 && date <= 19 ))
    {
         cout<<" Your zodiac sign is CAPRICORN\n";
         
    }
    else
    {
        cout<<" INVALID INPUT\n";
    }
    cout<<"do you want to continue? y/n"<<endl;
    cin>>ans;
    }
    if ( ans == 'n')
    {
         cout<<"Thank you for your precious time! :D\n\n";
    }

     system("pause");

}
but now i have another problem..the problem is i need to have a invalid input when the program asks "do you want to continue? Y/N"..for ex:

Do you want to continue? Y/N :
z (this is the input)
Sorry, i can only determine yes or no.

something like that..