l = list(input())
mx = len(l) - list(reversed(l)).index(max(l)) - 1
if mx != 0:
    for i in range(len(l)):
        if mx > i:
            if int(l[mx]) > int(l[i]):
                l[mx], l[i] = l[i], l[mx]
                break
        else:
            mx = len(l) - list(reversed(l)).index(max(l[i+1:])) - 1

print(''.join(l))