input = open("./input.txt", "r")

def inRange(num, start, end):
  if (num < start):
    return False
  if (num > end):
    return False
  return start <= num <= end

total = 0

for line in input:
  trimmedLine = line.replace("\n", "")
  elves = trimmedLine.split(",")
  elf1 = elves[0].split("-")
  elf1 = [int(elf1[0]), int(elf1[1])]
  elf2 = elves[1].split("-")
  elf2 = [int(elf2[0]), int(elf2[1])]
  elf2 = range(elf2[0], elf2[1] + 1)
  elf1 = range(elf1[0], elf1[1] + 1)
  elf1IsInElf2Range = False
  elf2IsInElf1Range = False
  for numbr in elf1:
    if (inRange(numbr, elf2[0], elf2[len(elf2) - 1])):
      elf1IsInElf2Range = True
      break
  for numbr in elf2:
    if (inRange(numbr, elf1[0], elf1[len(elf1) - 1])):
      elf2IsInElf1Range = True
      break
  if (elf2IsInElf1Range or elf1IsInElf2Range):
    total += 1

print(total)