#!/usr/bin/perl -wT
use strict;

my $low = 0;
my $high = 40000;

# guesses integet between two other integers
my $ans = '';
while ($ans ne 'C') {
  my $mid=int (($low+$high)/2);
  print "is $mid low, high or correct? :";
  $ans=<STDIN>;
     
  $ans=uc(substr($ans,0,1));
  if('L' eq $ans){
    $low = $mid+1;
  }elsif('H' eq $ans){
    $high = $mid-1;
  }elsif($ans ne 'C') {
    print "bad input\n";
  }     
}
print "thank you for playing\n";