n=int(input())
a=[]
b=[]
for i in range(n):
    a.append(list(map(int,input().split())))
for i in range(n):
    b.append(list(map(int,input().split())))
an=sorted(a, key=lambda x:-x[1])
bn=sorted(b)#, key=lambda x:(x[0],x[1]))
count=0
for i in range(len(bn)):
    for j in range(len(an)):
#        print(an[j],bn[i])
        if bn[i][0]>an[j][0] and bn[i][1]>an[j][1]:
            count+=1
            an.pop(j)
            break
 
print(count)