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