#!/usr/bin/perl -w
# pic 3.14: fig03_14.pl
# Расчет затрат бензина на километр пути

# Этап инициализации
$FullDistance = 0;
$FullBenzineConsumption = 0;
%Ratio = 0;


# Этап ввода значений
print "\nInput benzin consumption, l ( -1 if exit): ";
chomp ( $BenzineConsumption = <STDIN> );
if ( $BenzineConsumption > 0 )
{
   print "Input distance, km: ";
   chomp ( $Distance = <STDIN> );
   if ($Distance > 0 )
   {
      $FullDistance += $Distance;
      $FullBenzineConsumption += $BenzineConsumption;
      $Ratio = $BenzineConsumption / $Distance;
      print "For this tank benzine consumption $Ratio l per km.\n";
   }
   else
   {
      print "Impossible distance.\n";
      $Distance = 0;
   }
}
while ( $BenzineConsumption > 0 )
{
   print "\nInput benzin consumption, l ( -1 if exit): ";
   chomp ( $BenzineConsumption = <STDIN> );
   if ( $BenzineConsumption > 0 )
   {
      print "Input distance, km: ";
      chomp ( $Distance = <STDIN> );
      if ($Distance > 0 )
      {
         $FullDistance += $Distance;
         $FullBenzineConsumption += $BenzineConsumption;
         $Ratio = $BenzineConsumption / $Distance;
         print "For this tank benzine consumption $Ratio l per km.\n";
      }
      else
      {
         print "Impossible distance.\n";
         $Distance = 0;
      }
   }
}

# Километраж, средний и общий расход бензина
if ( $Ratio == 0 )
{
   print "You getting nowhere";
}
else
{
$FullRatio = $FullBenzineConsumption / $FullDistance;
print "Full distance: $FullDistance.\n";
print "Full benzine consumption: $FullBenzineConsumption.\n";
print "Average benzine consumption: $FullRatio.\n";
}