#!/usr/bin/env python

import re
import argparse

DIRECTIONS = [
    {'dir': 'N', 'V': 1, "H": 0 },
    {'dir': 'W', 'V': 0, "H": -1 },
    {'dir': 'S', 'V': -1, "H": 0 },
    {'dir': 'E', 'V': 0, "H": 1 }
]
DIRECTION_CHANGE = {
    'L': -1,
    'R': 1
}


def load_file(filename):
    with open(filename) as f:
        data = f.read()
    return data

def main(args):
    DIRECTION_INDEX = 0
    MAP_POSITION = [0, 0]

    for INDICE in load_file(args.input).split(','):
        INDICE = INDICE.strip()
        TURN = INDICE[0]
        STEP = int(INDICE[1:].strip())
        DIRECTION_INDEX = DIRECTION_INDEX + DIRECTION_CHANGE[TURN]
        if DIRECTION_INDEX < 0:
            DIRECTION_INDEX = len(DIRECTIONS) - 1 
        if DIRECTION_INDEX >= len(DIRECTIONS):
            DIRECTION_INDEX = 0
        MAP_POSITION[0] = MAP_POSITION[0] + DIRECTIONS[DIRECTION_INDEX]['V']*STEP 
        MAP_POSITION[1] = MAP_POSITION[1] + DIRECTIONS[DIRECTION_INDEX]['H']*STEP

    print("%d" % (abs(MAP_POSITION[0]) + abs(MAP_POSITION[1])))

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='AdventOfCode 2016 Day 01')
    parser.add_argument('--input', '-i', action='store',  required=True, help='input file')
    args = parser.parse_args()

    main(args)