#include <algorithm>
#include <cmath>
#include <cstdio>
#include <deque>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

using namespace std;

typedef long long ll;

#define MOD 1000000007

int main() {
  string s;
  cin >> s;
  int n = s.size();
  set<int> st;
  for (int i = 0; i < n; ++i) {
    if (s[i] == 'c') {
      for (int j = i + 1; j < n; ++j) {
        if (s[j] == 'w') {
          for (int k = j + 1; k < n; ++k) {
            if (s[k] == 'w') {
              st.insert(k - i + 1);
            }
          }
        }
      }
    }
  }
  if (st.empty()) {
    cout << -1 << endl;
  } else {
    cout << *st.begin() << endl;
  }
  return 0;
}