def replaceDuplicate(s):
#@param s: string
#@return newS: string
   i=0
   j=0
   newS=""
   while(i<len(s)-1)and(j<len(s)-1):
      j=j+1
      if (s[i]!=s[j])and(not s[i] in newS):
         newS=newS+s[i]
      if (not s[j] in newS):
            newS=newS+s[j]
      elif s[j]!=" ":
          newS=newS+"*"
      else: newS=newS+s[j]
   return newS