use strict;
use warnings;

my ($l, $r, $before, $after);

$before = [qw(1 2 3 4 5 6 7 8 9 10)];

while (<DATA>) {
    chomp;
    $after = [split / /];

    for ($l = 0; $before->[$l] == $after->[$l]; $l++) {}
    for ($r = $#$before; $before->[$r] == $after->[$r]; $r--) {}

    if ($l == $r - 1) {
        print "Either $after->[$l] moved to position $l, or $after->[$r] to position $r.\n";
    }
    elsif ($before->[$l] == $after->[$l+1]) {
        print "$after->[$l] moved to position $l\n";
    }
    else {
        print "$after->[$r] moved to position $r\n";
    }
}

__DATA__
10 1 2 3 4 5 6 7 8 9
2 3 4 5 6 7 8 9 10 1
1 10 2 3 4 5 6 7 8 9
2 3 4 5 6 7 8 9 1 10
1 2 3 4 5 6 8 7 9 10