N=int(input())
M=N
S=str(N)
for i in range(0,len(S)):
  for j in range(i+1,len(S)):
    if S[i]<S[j]:
      T=S[0:i]+S[j:j+1]+S[i+1:j]+S[i:i+1]+S[j+1:]
      if M<int(T): M=int(T)
  if M>N: break
print(M)