#!/usr/bin/perl
use v5.35.0;
use List::Util 'sum';

# Parse input map

my $width = 100;
my (@wall, @goods, $start);
my $size = 0;
while (defined($_ = <>) && /./) {
	for ((split //), (' ') x ($width - length)) {
		$wall[$size] = +/[\s#]/;
		$goods[$size] = +/O/;
		$start = $size if /@/;
		$size++;
	}
}

# Walk around as directed

my $robot = $start;
while (<>) {
	for (split //) {
		my $dir = index '^>v<', $_;
		if ($dir >= 0) {
			my $step = (-$width, 1, $width, -1)[$dir];
			my $pos = $robot + $step;
			$pos += $step while $goods[$pos];
			unless ($wall[$pos]) {
				$robot += $step;
				$goods[$pos] = $goods[$robot];
				$goods[$robot] = 0;
			}
		}
	}
}

# Deliver the goods

say sum map {$goods[$_] && $_} (0 .. $#goods);