#!/usr/bin/perl

use strict;

my %records;
while (<DATA>) {
    chomp;
    my @values = split( "_" );
    next unless $values[2] eq 'max';

    $records{ $values[0] } = $values[1]
      if ( $records{ $values[0] } > $values[1] ||
         ! $records{ $values[0] } );
}

print map { "$_ => $records{$_} \n" } keys %records;

__DATA__
111aaa222ccc324567fed54333221235_1.04
111aaa222ccc324567fed54333221235_1.05_max
111aaa222ccc324567fed54333221235_0.98_min
111aaa222ccc324567fed54333221235_1.02_max
111aaa222ccc324567fed54333221235_0.21
777aaa222ccc324567fed54333221235_1.04
777aaa222ccc324567fed54333221235_1.07_min
777aaa222ccc324567fed54333221235_1.04_max