N = list(map(int,input().strip()))
num = len(N)

for i in range(num):
    id = -1
    cmax = N[i] + 1
    for j in range(i+1,num):
        if N[j] >= cmax:
            cmax = N[j]
            id = j

    if id != -1:
        N[i],N[id] = N[id],N[i]
        break

ans = "".join([str(x) for x in N])
print(ans)