S=list(input())
ans=int(str("".join(S)))
N=len(S)
for i in range(N):
    for j in range(i+1,N):
        S[i],S[j]=S[j],S[i]
        ans=max(ans,int(str("".join(S))))
        S[i],S[j]=S[j],S[i]
print(ans)