class LinkedList:
    def __init__(self, array):
        self.first = Node("", 1, None, None)
        current_el = self.first
        for element in array:
            if current_el.value == element:
                current_el.count += 1
            else:
                current_el.next_el = Node(element, 1, current_el, None)
                current_el = current_el.next_el

    @staticmethod
    def insert_before(insertable_el, count_insertable_el, el_in_array):
        node = Node(insertable_el, count_insertable_el, el_in_array.past_el, el_in_array)
        if el_in_array.past_el is not None:
            el_in_array.past_el.next_el = node
        el_in_array.past_el = node

    @staticmethod
    def insert_after(insertable_el, count_insertable_el, el_in_array):
        node = Node(insertable_el, count_insertable_el, el_in_array, el_in_array.next_el)
        if el_in_array.next_el is not None:
            el_in_array.next_el.past_el = node
        el_in_array.next_el = node

    @staticmethod
    def delete_char(char):
        left = char.past_el
        left.next_el = char.next_el
        right = char.next_el
        if right is not None:
            right.past_el = left
            if left.value == right.value:
                LinkedList.union(left, right)
        return left

    @staticmethod
    def union(left, right):
        left.count += right.count
        left.next_el = right.next_el
        if right.next_el is not None:
            right.next_el.past_el = left

    def __str__(self):
        text_in_list = []
        current_el = self.first.next_el
        while current_el is not None:
            text_in_list.append(current_el.value * current_el.count)
            current_el = current_el.next_el
        return "".join(text_in_list)


class Node:
    def __init__(self, value, count, past_el, next_el):
        self.value = value
        self.count = count
        self.past_el = past_el
        self.next_el = next_el


def main():
    initial_code = input()
    code_mutants = LinkedList(initial_code)
    message_about_modifiers = input()
    modifiers = dict()
    for letter in message_about_modifiers:
        if letter in modifiers.keys():
            modifiers[letter] += 1
        else:
            modifiers[letter] = 1
    for letter_in_alp in sorted(modifiers.keys(), reverse=True):
        current_el = code_mutants.first.next_el
        while True:
            if letter_in_alp < current_el.value:
                code_mutants.insert_before(letter_in_alp, modifiers[letter_in_alp], current_el)
                break
            elif letter_in_alp > current_el.value:
                if current_el.next_el is None:
                    if modifiers[letter_in_alp] % 2 == 0:
                        break
                    else:
                        code_mutants.insert_after(letter_in_alp, 1, current_el)
                    break
                else:
                    current_el = current_el.next_el
            else:
                if current_el.next_el is None or current_el.next_el.value < letter_in_alp:
                    if current_el.count <= modifiers[letter_in_alp]:
                        modifiers[letter_in_alp] -= current_el.count
                        current_el = code_mutants.delete_char(current_el)
                        if modifiers[letter_in_alp] == 0:
                            break
                    else:
                        current_el.count -= modifiers[letter_in_alp]
                        break
                else:
                    current_el.count += modifiers[letter_in_alp]
                    break
    print(str(code_mutants))


if __name__ == "__main__":
    main()