#!/usr/bin/perl while ($line = <STDIN>) { if(not $line) { exit; } ($col1,$col2) = split(/\s/, $line); $count1 = 0; $count2 = 1; $old_col1 = $col1; $old_col2 = $col2; while($line = <STDIN>) { ($col1,$col2) = split(/\s/, $line); if ($col1 ne $old_col1 || </stdin></stdin>…