#include <iostream>
#include <string>
#include <algorithm>
#define INF 1000
using namespace std;

int main() {
  string s;
  cin >> s;
  int ans = INF;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == 'c') {
      bool f = false;
      for (int j = i + 1; j < s.size(); j++) {
        if (s[j] == 'w' && !f) {
          f = true;
        } else if (s[j] == 'w' && f) {
          ans = min(ans, j - i + 1);
          break;
        }
      }
    }
  }
  cout << (ans != INF ? ans : -1) << endl;
  return 0;
}