from collections import deque
def cltime(A, i):
    return A[i][0] * 60 + A[i][1]
def hours(time):
    return [time // 60, time % 60]
def queue(A, B):
    q = 0
    for j in range(len(B)):
        if cltime(B, j) > cltime(A, 0):
            q += 1
    return q
def endtime(A, B):
    T = cltime(A, 0)
    for j in range(len(B)):
        if cltime(B, j) > T:
            T = cltime(B, j)
    return T + 20


n = int(input())
A = []
for i in range(n):
    A.append(list(map(int, input().split())))
A = deque(A)
B = []
B.append(hours(cltime(A, 0) + 20))
A.popleft()
while len(A) > 0:
    if A[0][2] < queue(A, B):
        B.append(A[0][:2])
    else:
        B.append(hours(endtime(A, B)))
    A.popleft()
for i in B:
    print(*i)