using System;
public class Yuki436{
  public static void Main(){
    string s = Console.ReadLine();
    int ss = s.Length;
    int pos=0;
    for(int i=0;i<ss;++i){
      char a = s[i];
      if(a=='w'){
        pos=i+1;
        break;
      }
    }
    int ans=0;
    if(pos<=ss/2+1){
      ans=pos-2;
    } else {
      ans=ss-pos+1;
    }
    Console.WriteLine("{0}",ans);
  }
}