#include <iostream>
#include <string>
using namespace std;

int main(void)
{
  int i, j, cou=0, w = 0, min = 200;
  string str;
  cin >> str;
  for(i=0;i<str.length();i++){
    if(str[i] == 'c'){
      cou = 1;
      w = 1;
      for(j=i+1;j<str.length();j++){
        if(str[j] == 'w')w++;
        if(w>2)if(min>j-i+1)min = j-i+1;
      }
    }
  }
  if(min!=200)cout << min << endl;
  else cout << "-1" << endl;
  return 0;
}