Revise paste Memory Game

initial_string = input().split()

move_counter = 0
command = input()
while command != "end":
    
    command_split = command.split()
    index_1 = int(command_split[0])
    index_2 = int(command_split[1])
    
    move_counter += 1
    
    if 0 <= index_1 < len(initial_string) and 0 <= index_2 < len(initial_string):
        value_1 = initial_string[index_1]
        value_2 = initial_string[index_2]
        if value_1 == value_2:
            print(f"Congrats! You have found matching elements - {value_1}!")
            initial_string.remove(value_1)
            initial_string.remove(value_2)
        
        else:
            print(f"Try again!")
            
            
    else:
        print(f"Invalid input! Adding additional elements to the board")
        middle_point = int(len(initial_string) // 2)
        for el in range(move_counter):
            initial_string.insert(middle_point, f"-{str(move_counter)}a")
            
    if len(initial_string) == 0:
        print(f"You have won in {move_counter} turns!")
        break
            
    
    command = input()
    
if len(initial_string) != 0:
    print(f"Sorry you lose :(")
    print(" ".join(initial_string))