use File::Copy;
use File::Spec::Functions qw(catfile);

use constant SRCDIR => '/tmp/src';
use constant DESTDIR => '/tmp/dest';

my @file = do {
    opendir my($dirh), SRCDIR or die $!;
    readdir $dirh;
};

while(@file > 2) {
    my $tomove = splice @file, (-M $file[0] < -M $file[1] ? 1 : 0), 1;
    move(catfile(SRCDIR, $tomove), catfile(DESTDIR, $tomove));
}