use strict;
use warnings FATAL => 'all';

use List::Utils qw( sum );

my $input = do {
    local $/;
    <>;
};

my %letters;
$letters{$_}++ for grep /\w/, split //, $input;

my $total = sum values %letters;

for ( sort keys %letters ) {
    printf "%s\t%d\t%.3f\n", $_, $letters{$_}, $letters{$_}/$total;
}

print "$total characters\n";