N = int(input())
AB = [map(int, input().split()) for _ in range(N)]
A, B = [list(i) for i in zip(*AB)]

zip_lists = zip(B,A)
zip_sort = sorted(zip_lists)
B,A = zip(*zip_sort)

prev_f = 0
cnt = 0
for i in range(N):
  if prev_f <= A[i]:
    prev_f = B[i]
    cnt += 1
print(N-cnt)