N = input()
array = list(N)
sorted_list = sorted(array, reverse=True)

for i in range(len(N)):
    if array[i] != sorted_list[i]:
        switch = sorted_list[i]
        for j in range(len(array) - 1, i, -1):
            if array[j] == switch:
                array[i], array[j] = array[j], array[i]
                break
        break

print("".join(array))