#!/usr/bin/perl
use strict;
use warnings;
# 767362


my $out_line;
my @line = <DATA>;
for my $line (@line) {
	chomp $line;
	$out_line .= ( $line . "/" );
}
if ( $out_line =~ /(.*)\/$/ ) {  # capture everything before a slash immediately preceding EOL
	$out_line = $1;          # and overwrite $out_line with what you captured
}
print $out_line . "\n";

__DATA__
10
9999
456
...