#!/usr/bin/perl

use strict;
use warnings 'all';

my @info;

while (<DATA>) {
    my ($num, $info) = split ' ', $_, 2;

    if (@info && $num == $info [-1] [0]) {
        $info [-1] [2] ++;
    }
    else {
        push @info => [$num, $info, 1]
    }
}

print map {"@{$_}[0, 1]"} sort {$b -> [2] <=> $a -> [2]} @info;

__DATA__
1  info1
1  info1
1  info1
2  info2
3  info3
3  info3
4  info4
4  info4
4  info4
4  info4



$ ./count
4 info4
1 info1
3 info3
2 info2
$