str1 = input() str2 = input() num_count1 = sum(1 for c in str1 if c.isdigit()) num_count2 = sum(1 for c in str2 if c.isdigit()) if num_count1 > num_count2: result = str2[::-1] + str1[num_count1 - 1] elif num_count2 > num_count1: result = str1[::-1] + str2[num_count2 - 1] else: result = str1[::-1] + str2[0] print(result)