import sys

def solve():
    N = int(input())
    hako = [sorted([int(i) for i in input().split()]) for j in range(N)]
    hako.sort()

    inf = 10**9

    dp = [[inf, inf, inf] for i in range(N)]
    dp[0] = hako[0]

    for i in range(1, N):
        for j in range(N):
            if not is_larger(dp[j], hako[i]):
                if is_larger(hako[i], dp[j]):
                    dp[j] = hako[i]

                break

        # print(dp)

    ans = len([tyoku for tyoku in dp if tyoku != [inf]*3])
    print(ans)

def is_larger(a, b):
    for i in range(3):
        if b[i] <= a[i]:
            return False

    return True

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

if __name__ == '__main__':
    solve()