import itertools

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

print(ans)