n = list(input())
l = len(n)
ans = int("".join(n))
for i in range(l):
    for j in range(i + 1, l):
        n[i], n[j] = n[j], n[i]
        ans = max(ans, int("".join(n)))
        n[i], n[j] = n[j], n[i]
print(ans)