N = list(input())
max = int("".join(N))

for i in range(len(N)):
    for j in range(len(N)):
        if i == j:
            continue

        N[i], N[j] = N[j], N[i]

        if max < int("".join(N)):
            max = int("".join(N))

        N[j], N[i] = N[i], N[j]

print(max)