06.Substitute

first_number = int(input())
second_number = int(input())
third_number = int(input())
fourth_number = int(input())
are_they_right = False
number_of_changes = 0
subs = 0

for first in range(first_number,9):
    if first % 2 == 0:
        for second in range(9,second_number - 1,-1):
            if second % 2 != 0:
                for third in range(third_number,9):
                    if third % 2 == 0:
                        for fourth in range(9,fourth_number - 1,-1):
                            if fourth % 2 != 0:
                                if first == third and second == fourth:
                                    print("Cannot change the same player.")
                                else:
                                    subs += 1
                                    print(f"{first}{second} - {third}{fourth}")
                                    if subs == 6:
                                        are_they_right = True
                                        exit()