import sys def merge_str(str_1, str_2): new_str = str_1 + str_2 new_str_1 = '' new_str_2 = '' for i in range(1, len(new_str) + 1): if i % 2 == 0: new_str_2 += new_str[i - 1] else: new_str_1 += new_str[i - 1] sorted_str_1 = iter(sorted(new_str_1)) sorted_str_2 = iter(sorted(new_str_2)) ret_str = '' for i in range(1, len(new_str) + 1): if i % 2 == 0: ret_str += next(sorted_str_2) else: ret_str += next(sorted_str_1) return ret_str def encode_str(input_str): result = '' enc_str = '1234567890abcdefABCDEF' for i in input_str: if i in enc_str: int_i = int('0x' + i, 16) revers_b = '{:04b}'.format(int_i)[::-1] chr_i = hex(int(revers_b, 2)).replace('0x', '') if chr_i.isalpha(): result += chr_i.upper() else: result += chr_i else: result += i return result def main(): while True: input_str_1 = sys.stdin.readline().strip() if input_str_1 == '': break merged_str = merge_str(*input_str_1.split()) print(encode_str(merged_str)) main()