num = input()
l = len(num)
N = [""] * l

for i in range(l):
    N[i] = num[i]

N2 = N[:]
change = ""

for i in range(l):
    change += N[i]
ans = int(change)

for i in range(l):
    for j in range(i+1, l):
        N2 = N[:]
        tmp = N[i]
        N2[i] = N[j]
        N2[j] = tmp
        change = ""

        for k in range(l):
            change += N2[k]

        ans = max(ans, int(change))

print(ans)