#! perl -slw
use strict;

my $NUM = $ARGV[ 0 ] || die 'No arg';

my $root = sqrt( $NUM );
my( $lo, $hi ) = ( int( $root ), int( $root + 1 ) );;

$lo-- while $NUM % $lo;
$hi++ while $NUM % $hi;

my $near = ( $lo, $hi )[ abs( $root - $lo ) > abs( $root - $hi ) ];

print "$NUM ($root) : $near";