n = [x for x in input()]
max_num = max(n)

for index, num in enumerate(n):
    target = max(n[index:])
    if int(num) < int(target):
        lists_index = [x for x, num2 in enumerate(n) if num2 == target and x > index]
        replace_index = lists_index.pop()
        n[index], n[replace_index] = target, num
        print(int(''.join(n)))
        break

else:
    print(int(''.join(n)))