#include <iostream>
#include <string>

using namespace std;

int main() {
  string s;
  cin >> s;
  for (size_t i = 0; i < s.size(); ++i) {
    if (s[i] == 'c') {
      int count = 0;
      for (size_t j = i + 1; j < s.size(); ++j) {
        if (s[j] == 'w') {
          ++count;
          if (count == 2) {
            cout << j + 1 - i << endl;
            return 0;
          }
        }
      }
    }
  }
  cout << -1 << endl;
  return 0;
}