n = list(map(int, input()))
now_max_i = len(n) - 1
max_num = max(n, key=lambda x: int(x))
flag = False
i = 0
while n[i] == max_num:
    i += 1
if i == len(n):
    print("".join(map(str, n)))
    exit()
swap_index = i
for i in range(len(n)-2,-1,-1):
    if n[now_max_i] < n[i]:
        now_max_i = i
n[now_max_i],n[swap_index] = n[swap_index], n[now_max_i]

print("".join(map(str, n)))