use warnings;
use strict;

my $id = '-' x 50;
print "$id\n";

while (<DATA>) {
    chomp;
    my ($s, $e) = split /\-/;
    my $copy = $id;
    my $len = $e - $s + 1;
    substr($copy, $s-1, $len) = 'A' x $len;
    print "$copy\n";
}

__DATA__
7-10
12-40

##</code><code>##

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