#!/usr/bin/perl
use strict;
use warnings;

my $fh = \*STDIN;    # For test input, change to: \*DATA
###my $fh = \*DATA;    # For user input, change to: \*STDIN

print "\nMulti Gear Calculator\n\n";

print "Enter Wheelsize (inches): ";
my    $wheel = <$fh>;
print $wheel;
chomp $wheel;


print "Enter Chainwheel Teeth:   ";
my    $chainWheels = <$fh>;
print $chainWheels;
my    @chainWheels = split /\s+/, $chainWheels;

print "Enter Cog Teeth:          ";
my    $cogs  = <$fh>;
print $cogs;
my    @cogs  = split /\s+/, $cogs;


print "Wheelsize:   $wheel\n";
print "Chainwheels: @chainWheels\n";
print "Cogs:   @cogs\n\n";

for my $chainSel (1 .. @chainWheels) {
    my $wheelMul = $wheel * $chainWheels[$chainSel - 1];

    print "Chain wheel: $chainSel ratios:  \n";

    for my $cogSel (1 .. @cogs) {
        printf "%5.2f  ", $wheelMul / $cogs[$cogSel - 1];
    }

    print "\n";
}

__DATA__
26.5
42 32 22
11 13 15 17 19 21 24 28 32