const eql = std.mem.eql;
const parseUnsigned = std.fmt.parseUnsigned;
const print = std.debug.print;
const std = @import("std");
const tokenize = std.mem.tokenize;

pub fn main() !void {
    var position = @as(usize, 0);
    var depth = @as(usize, 0);
    defer print("{}\n", .{ position * depth });

    var input = tokenize(@embedFile("input"), "\n");
    while (input.next()) |line| {
        var command = tokenize(line, " ");
        const direction = command.next().?;
        const x = try parseUnsigned(usize, command.next().?, 10);
        if (eql(u8, direction, "forward"))
            position += x
        else if (eql(u8, direction, "down"))
            depth += x
        else if (eql(u8, direction, "up"))
            depth -= x
        else unreachable;
    }
}