s = list(input())
pre = []

def list2int(x):
  x = "".join(x)
  return int(x)

for i in range(len(s)):
  for j in range(len(s)):
    if i==j:continue
    a = s[i]
    b = s[j]
    s[j]=a
    s[i]=b
    pre.append(list2int(s))
    
    
print(max(pre))