#yuki927
import sys

x=[c for c in raw_input()]
x=sorted(x,reverse=True)
if x[0]==x[-1] or x[1]=='0':
 print -1
 sys.exit()
for i in range(len(x)-1,0,-1):
 if x[i]!=x[i-1]:
  x[i],x[i-1]=x[i-1],x[i]
  break
res=''
for i in range(len(x)):
 res+=x[i]
print res