def matching():
    n = int(input())
    stu = [list(input().strip().split()) for _ in range(n)]
    ans = []
    maxn = 0
    for i in range(n):
        for j in range(i + 1, n):
            a = b = t = 0
            for k in range(1, 4):
                if abs(int(stu[i][k]) - int(stu[j][k])) <= 5:
                    a += int(stu[i][k])
                    b += int(stu[j][k])
                    t += 1
            if abs(a - b) <= 10 and t == 3:
                maxn += 1
                m = [stu[i][0], stu[j][0]]
                m.sort()
                ans.append(m)

    ans.sort(key=lambda x: (x[0], x[1])) # 按列表的第一个元素排序

    for i in range(maxn):
        print(ans[i][0], ans[i][1])


matching()