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

if($#ARGV<0){
    die "Usage: $0 <*.txt>\n";
}

open(IN,$ARGV[0]) ;

$/ = "\n\n";

while ( <IN> ) {
    if( my( $number ) = m/(\d+)/ ) {
        s/\b\p{Alpha}+\b/$number/g;
    } else {
        warn "Malformed record in input line $.\n$_\nContinuing.\n";
    }
    print;
}