#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main(){
  string s;
  cin >> s;
  int ret = 101;
  for( int i=0; i<s.size(); i++ ){
    if( s[i] == 'c' ){
      int c = 0;
      for( int j=i+1; j<s.size(); j++ ){
        if( s[j] == 'w' ) c++;
        if( c == 2 ){
          ret = min( ret, j-i+1 );
          break;
        }
      }
    }
  }
  if( ret > 100 ) cout << -1 << endl;
  else cout << ret << endl;
}