import itertools

N = list(input())


def toint(num_lst):
    return int(''.join(map(str, num_lst)))


ans = toint(N)
for i, j in itertools.combinations(range(len(N)), 2):
    num_lst = N.copy()
    num_lst[i], num_lst[j] = num_lst[j], num_lst[i]
    ans = max(ans, toint(num_lst))
print(ans)