fn decode(b : bytes) := (26 * 26) * (b[0] - 'A') + 26 * (b[1] - 'A') + (b[2] - 'A');

fn main
[
	var lines := list_break_to_lines(read_lazy(h[0]));

	var steps := infinite_repeat(lines[0]);
	lines := lines[2 .. ];
	var a := array_fill(mktuple2(-1, -1), [ipower(26, 3)]);
	for line in lines do [
		var id := decode(line[ .. 3]);
		var left := decode(line[7 .. 10]);
		var right := decode(line[12 .. 15]);
		a[id].v1 := left;
		a[id].v2 := right;
	]
	var pos := 0;
	var counter := 0;
	while pos <> ipower(26, 3) - 1 do [
		if steps[0] = 'L' then
			pos := a[pos].v1;
		else if steps[0] = 'R' then
			pos := a[pos].v2;
		else
			abort;
		steps := steps[1 .. ];
		counter += 1;
	]
	write(h[1], ntos(counter) + nl);
]