n = list(map(int, list(input())))

j = -1
jv = -1
for i in range(len(n)):
    if jv <= n[i]:
        jv = n[i]
        j = i

k = j
for i in range(j):
    if n[i] < jv:
        k = i
        break

n[k], n[j] = n[j], n[k]
print(''.join(map(str, n)))