#include <algorithm>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <utility>
#include <vector>


using namespace std;


using ll = long long;
using ld = long double;


#define all(v) v.begin(), v.end()
#define rep(i, n) for (ll i = 0; i < n; ++i)
#define rep2(i, n, m) for (ll i = n; i <= m; ++i)
#define rep3(i, n, m) for (ll i = n; i >= m; --i)


template<class T> using pqg = priority_queue<T, vector<T>, greater<T>>;
template<class T> using pq  = priority_queue<T>;


template<class S, class T> inline bool chmax(S &a, T b) { if (a < b) { a = b; return true; } return false; }
template<class S, class T> inline bool chmin(S &a, T b) { if (a > b) { a = b; return true; } return false; }


string s;
int n, ans;

int main() {
  cin >> s;
  n = s.size();
  ans = n+1;

  rep(i, n) rep2(j, i+1, n-1) rep2(k, j+1, n-1) {
    if (s[i] == 'c' && s[j] == 'w' && s[k] == 'w') {
      chmin(ans, k - i + 1);
    }
  }

  cout << (ans == n+1 ? -1 : ans) << endl;
  return 0;
}