from operator import itemgetter

n = int(input())
r = []
b = []
c = 0
for i in range(n):
  r.append(list(map(int,input().split())))
for i in range(n):
  b.append(list(map(int,input().split())))
r.sort(key = itemgetter(1),reverse = True)
b.sort(key = itemgetter(0))
for i in range(n):
  for j in range(n):
    if b[i][0] > r[j][0] and b[i][1] > r[j][1]:
      r[j] = [10**6,10**6]
      c += 1
      break
print(c)
    
