n=int(input())
l=[int(i) for i in str(n)]
length=len(l)
pt=0
for i in range(length-1,0,-1):
    if(l[i-1]<l[i]):
        pt=i-1
        break
if(pt==0):
    l.sort()
    res=''.join([str(i) for i in l])
    print(res)
else:    
    for i in range(length-1,pt,-1):
        if(l[i]>l[pt]):
            l[i],l[pt]=l[pt],l[i]
            break
    ans=l[:pt+1]+l[pt+1:][::-1]
    res=''.join([str(i) for i in ans])
    print(res)