sequence_numbers = input()
list_strings = sequence_numbers.split(" ")
message_string = input()
final_message = ""
sum_numbers = 0
counter = 0
for item in list_strings:
    sum_numbers = 0
    for index in range(len(item)):
        sum_numbers += int(item[index])
    while counter < sum_numbers:
        for message in range(len(message_string)):
            if counter == sum_numbers:
                print(f"{message_string[message]}", end="")
                message_string = message_string.replace(message_string[message], "", 1)
                break
            counter += 1
    counter = 0