# PART 1


def find_doubles(steps):
    x, y = 0, 0
    houses = {(0, 0)}
    for step in steps:
        if step == "^":
            y += 1
        elif step == "v":
            y -= 1
        elif step == "<":
            x -= 1
        elif step == ">":
            x += 1
        houses.add((x, y))
    return houses


# PART 2


def split_string(s):
    s1 = ""
    s2 = ""
    while True:
        if not s:
            break
        s1 += s[0]
        s = s[1:]
        if not s:
            break
        s2 += s[0]
        s = s[1:]
    return s1, s2


def solve(inputstr):
    steps = inputstr.strip()
    doubles = len(find_doubles(steps))
    print(f"Part 1: {doubles}")
    santa, robot = split_string(steps)
    santa_doubles = find_doubles(santa)
    robot_doubles = find_doubles(robot)
    doubles_2 = len(santa_doubles | robot_doubles)
    print(f"Part 2: {doubles_2}")