N = input().rstrip()
MAX = N
for i in range(0, len(N)):
    M = N[i]
    for j in range(i + 1, len(N)):
        if M <= N[j]:
            M = N[j]
            S = list(N)
            S[i], S[j] = S[j], S[i]
            MAX = max(MAX, "".join(S))
print(MAX)