def mainProc(lsts): dic = {} for i in range(1, 11) : dic[i] = 0 for lst in lsts : for j in range(3) : dic[lst[j]] += 1 total = 0 half = 0 for value in dic.values() : total += value // 2 half += value % 2 print(total + half // 4) if __name__ == '__main__': n = int(input()) lsts = [] for i in range(n) : lsts.append([int(i) for i in input().split()]) mainProc(lsts)