#!/usr/bin/env python

import math

MOVES = {
  'U': ( 0, -1),
  'D': ( 0, +1),
  'L': (-1,  0),
  'R': (+1,  0),
}

TAIL_POSITIONS = set([])
HEAD = (0, 0)
TAIL = (0, 0)

def point_add(a, b):
    return tuple(map(lambda i, j: i + j, a, b))

def move(delta):
    global TAIL_POSITIONS, HEAD, TAIL

    last_head = HEAD
    HEAD = point_add(HEAD, delta)

    if ed := math.dist(HEAD, TAIL) < 2.0:
        _ # do nothing
    elif ed == 2.0:
        TAIL = point_add(TAIL, delta)
    else:
        TAIL = last_head

    TAIL_POSITIONS.add(TAIL)

with open('input') as f:
    for line in f:
        direction, count = line.rstrip().split(" ")
        for _ in range(int(count)):
            move(MOVES[direction])

print(len(TAIL_POSITIONS))