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