AoC day 12 (pt1), Perl

#!/usr/bin/perl

use strict;
use warnings;

use List::AllUtils  qw(pairwise sum);

my %Dirs   = ( 'E' => [0,1], 'N' => [-1,0], 'W' => [0,-1], 'S' => [1,0] );
my @Widder = ( 'E', 'N', 'W', 'S' );

my $Face = 0;
my @Pos  = (0,0);

while (<>) {
    m#(\w)(\d+)#;

    if ($1 eq 'F') {
        @Pos = pairwise { $a + $2 * $b } @Pos, @{$Dirs{$Widder[$Face]}};
    } elsif ($1 eq 'L') {
        $Face = ($Face + ($2 / 90)) % 4;
    } elsif ($1 eq 'R') {
        $Face = ($Face - ($2 / 90)) % 4;
    } else {
        @Pos = pairwise { $a + $2 * $b } @Pos, @{$Dirs{$1}};
    }
}

print "Part 1: ", (sum map { abs } @Pos), "\n";