#!/usr/bin/perl -w
 $_=<<"EOD"
192.168.137.1
10.0.0.1
10.0.0.2.
423525.547547.7657.65765767567.567567.567567
lfdlhgdf.dhjgh.hg.g
10.0.0.3111
10.0.0.4.w
EOD
 ;
@ip= /(?:\d{1,3}\.){3}\d{1,3}(?<!\d\.)(?!\.\d|\d|\.\w)/g;
 $,=$/;
print @ip;