n = int(input())

empty=[]

i = 0
for _ in range(n):
    [a,b,c] =[int(i) for i in input().split(' ')]
    empty.append(a)
    empty.append(b)
    empty.append(c)
    if empty.count(a)==2:
        i+=1
        
    if empty.count(b)==2:
        i+=1
    
    if empty.count(c)==2:
        i+=1
    
s=[q for q in empty if empty.count(q)%2 !=0]

four_numebr=len(s)//4

print(i+four_numebr)