from itertools import combinations


def main():
    N = int(input())

    digits = list(str(N))
    candidates = [N]
    for idx_1, idx_2 in combinations(range(len(digits)), 2):
        digits_swapped = digits.copy()
        digits_swapped[idx_1], digits_swapped[idx_2] = \
            digits_swapped[idx_2], digits_swapped[idx_1]

        candidates.append(int("".join(digits_swapped)))
    print(max(candidates))


if __name__ == "__main__":
    main()