n = int(input())

num_dict = {}
for i in range(n):
    a_b_c = list(map(int, input().split(' ')))
    for item in a_b_c:
        if item in num_dict.keys():
            num_dict[item] += 1
        else:
            num_dict[item] = 1
            
cnt = 0
left = 0
for value in num_dict.values():
    left += value%2
    cnt += (value-value%2)/2

cnt += (left-left%4)/4

print(int(cnt))