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

@ARGV = ( '148Nsorted.bed', '162Nsorted.bed', '174Nsorted.bed', '175Nsorted.bed' );

my ( $bit_mask, %data ) = 1;

while ( <> ) {
    /^\s*(\S+)\s+(\d+)\s+(\d+)\s*$/ or next;
    $data |= chr( 0 ) x ( $2 - 1 ) . chr( $bit_mask ) x ( $3 - ( $2 - 1 ) );
    $bit_mask <<= 1;
    }

keys( %data ) == 1 or die "Error: too many keys: @{[ keys %data ]}\n";

my ( $name, $string ) = each %data;

$string =~ /\x0f/ or die "Error: no overlap on all files.";

$string =~ /[^\0]/ and my ( $start, $end ) = ( $+[ 0 ], length $string );

print "$name\t$start\t$end\n";