#include <bits/stdc++.h>

using namespace std;

bool check(string s) {
  int flag = 0;
  for (int i = 0; i < s.size(); i++) {
    if (flag == 0 && s[i] == 'c') flag = 1;
    else if (flag == 1 && s[i] == 'w') flag = 2;
    else if (flag == 2 && s[i] == 'w') flag = 3;
  }
  return flag == 3;
}

int main(void) {
  string s;
  cin >> s;

  int ans = 1000;
  for (int i = 0; i < s.size(); i++) {
    for (int j = i + 1; j < s.size(); j++) {
      if (check(s.substr(i, j - i + 1))) {
        ans = min(ans, j - i + 1);
      }
    }
  }

  cout << (ans == 1000 ? -1 : ans) << endl;

  return 0;
}