N = input()
array = list(N)
for i in range(len(N)):
    if int(array[i]) != sorted(list(map(int, array)))[-i-1]:
        switch_value = sorted(list(map(int, array)))[-i-1]
        switch_index = list(map(int, array)).index(switch_value)
        temp = array[i]
        array[i] = switch_value
        array[switch_index] = temp
        break
    else:
        pass
print(list(map(int, array)))