#include <iostream>
#include <string>

using namespace std;

int main() {
  string s;
  cin>>s;
  int m=-1;
  for ( int i=0,c=-1,cw=-1;i<s.size();i++ ) {
    if ( s[i]=='c' ) {
      c=i;
    }
    else if ( s[i]=='w' ) {
      if ( cw>=0&&(m<0||m>i-cw+1 ) ) {
        m=i-cw+1;
      }
      cw=c;
    }
  }
  cout<<m<<endl;
}