from copy import deepcopy

N = input()

list(N)
n = [0] * len(N)

for i in range(len(N)):
    n[i] = int(list(N)[i])
n2 = deepcopy(n)
n2.sort()
n2.reverse()

for i in range(len(N)):
    if n2[i] != n[i]:
        n3 = deepcopy(n)
        n3.reverse()
        k = n3.index(n2[i])
        n[len(N)-k-1] = n[i]
        n[i] = n2[i]
        break

result = 0
for i in range(len(N)):
    result += n[len(N) - i - 1] * (10 ** i)

print(result)