#include <iostream>
#include <fstream>
#include <string>
using namespace std;
void main (void)
{
int accountnumber;
char servicecode;
int minute;
int sms;
float payment;
int mremain;
int smsremain;
float mpayment;
float smspayment;
char YN;
int basicpayment;
string plan;
int freepaymins;
int freepaysms;
ofstream outData("bill.txt");
do
{
cout << "Welcome to ABC cellular telephony Automatic Bill Computation System" <<endl;
cout << "lease enter your account no: ";
cin >> accountnumber;
cout << "Which service are you using? [S]tudent, [R]egular or [P]remium: ";
cin >> servicecode;
cout << "Enter air time used (mins): ";
cin >> minute;
cout << "Enter number of SMSes sent: ";
cin >> sms;