#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  string s; cin >> s;
  int ret = 1<<20;
  for (int i = 0; i < s.length(); i++) {
    for (int j = i+1; j < s.length(); j++) {
      for (int k = j+1; k < s.length(); k++) {
        if (s[i] == 'c' && s[j] == 'w' && s[k] == 'w')
          ret = min(ret, k-i+1);
      }
    }
  }

  if (ret == 1<<20)
    ret = -1;
  cout << ret << endl;
  
  return 0;
}