x=[_ for _ in input()]
x.sort(reverse=True)
if len(set(x))==1:
  print(-1)
  exit()
for i in range(len(x)-1,-1,-1):
  if x[i]!=x[-1]:
    x[i],x[-1]=x[-1],x[i]
    break
if x[0]=="0":
  print(-1)
  exit()
print("".join(x))