import os

input = open(os.path.dirname(__file__) +
             "/input.txt", "r").readlines()

cave = set()

for l in input:
    points = l.strip().split(' -> ')
    prev = (0, 0)
    for p in points:
        x, y = p.split(',')
        x = int(x)
        y = int(y)
        if prev == (0, 0):
            prev = (y, x)
            cave.add(prev)
        else:
            dy = y-prev[0]
            dx = x-prev[1]
            tmp = set()
            dir = 1
            if dy < 0 or dx < 0:
                dir = -1
            if dy != 0:
                for i in range(prev[0], prev[0]+dy+dir, dir):
                    tmp.add((i, prev[1]))
            if dx != 0:
                for i in range(prev[1], prev[1]+dx+dir, dir):
                    tmp.add((prev[0], i))
            cave.update(tmp)
            prev = (y, x)


def nextdown(pos):
    possibles = []
    for y, x in cave:
        if x == pos[1] and y > pos[0]:
            possibles.append(y)
    return (sorted(possibles)[0]-1, X)


cont = True

emptycave = len(cave)

floor = max(r[0] for r in cave)+2
while cont:
    X = 500
    Y = 0
    current = nextdown((Y, X))
    moving = True
    while (moving):

        down = (current[0]+1, current[1])
        left = (current[0]+1, current[1]-1)
        right = (current[0]+1, current[1]+1)

        if not down in cave:
            current = down
            if current[0] >= floor:
                cont = False
                moving = False

        elif not left in cave:
            current = left
        elif not right in cave:
            current = right
        else:
            cave.add(current)
            moving = False

# print(sorted(cave))
print(len(cave)-emptycave)