from copy import deepcopy
N = list(map(int, list(input())))


ans = 0
for i in range(len(N)):
    for j in range(len(N)):
        N_copy = deepcopy(N)
        N_copy[i], N_copy[j] = N_copy[j], N_copy[i]
        ans = max(ans, int(''.join(map(str, N_copy))))

print(ans)