def main():
    N = int(input())
    A = tuple(tuple(map(int, input().split())) for _ in range(N))

    num = dict()
    for a, b, c in A:
        num[a] = num.get(a, 0) + 1
        num[b] = num.get(b, 0) + 1
        num[c] = num.get(c, 0) + 1

    powerup = 0
    item = 0
    for val in num.values():
        div_, mod_ = divmod(val, 2)
        powerup += div_
        item += mod_

    ans = powerup + item // 4
    print(ans)

main()