N = list(map(int, list(input())))

for n in reversed(range(1, 10)):
    positions_n = [p for p,v in enumerate(N) if v == n]
    if len(positions_n) > 0:
        n_pos = max(positions_n)
        for j in range(n_pos):
            if N[j] < N[n_pos]:
                N[j],N[n_pos] = N[n_pos],N[j]
                break
        else:
            continue
        break

print("".join(map(str, N)))