// This program repeatedly reads an income from
// the file income.in until end-of-file.
// Income under 6000 greenbacks is taxed at 30 
// percent, and income greater than or equal to 
// 6000 greenbacks is taxed at 60 percent. 
// After reading each income, the program 
// outputs the income and tax to the file tax.out.
#include <iostream>
#include <fstream>
#include <cstdlib>
using namespace std;
const int cutoff = 6000;
const float rate1 = 0.3;
const float rate2 = 0.6;
int main() {
   ifstream infile;
   ofstream outfile;
   infile.open( "income.in" );
   outfile.open( "tax.out" );
   if ( !infile ) {
      cout << "Unable to open income.in" << endl;
      exit( 0 );
   }
   if ( !outfile ) {
      cout << "Unable to open tax.out" << endl;
      exit( 0 );
   }
   int income, tax;
   while ( infile >> income ) {
      if ( income < cutoff )
         tax = rate1 * income;
      else
         tax = rate2 * income;
      outfile << "Income = " << income 
              << " greenbacks" << endl
              << "Tax = " << tax
              << " greenbacks" << endl;
   }
   infile.close();
   outfile.close();
   return 0;
}