l = list(input())
l = list(l)
for i in range(len(l)):
    mx = len(l) - list(reversed(l[i:])).index(max(l[i:])) - 1
    if mx > i:
        if int(l[mx]) > int(l[i]):
            l[mx], l[i] = l[i], l[mx]
            break
print(''.join(l))