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