#include <bits/stdc++.h>
#define rep(i, ss, ee) for (int i = ss; i < ee; ++i)
using namespace std;

int solve() {
  int ans = 1000;
  string s;
  cin >> s;
  vector<int> c, w;
  rep(i, 0, s.size()) {
    if (s[i] == 'c') c.emplace_back(i);
    if (s[i] == 'w') w.emplace_back(i);
  }
  rep(i, 0, c.size()) {
    rep(j, 0, w.size()) {
      if (c[i] < w[j] && w.size() - j > 0) {
        rep(k, j + 1, w.size()) ans = min(ans, w[k] - c[i] + 1);
      }
    }
  }
  if (ans == 1000) ans = -1;
  return ans;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << solve() << endl;
  getchar();
}