#include <bits/stdc++.h>
using namespace std;
int INF = 100000;
int main(){
  string S;
  cin >> S;
  int N = S.size();
  int ans = INF;
  for (int i = 0; i < N; i++){
    for (int j = i + 1; j < N; j++){
      for (int k = j + 1; k < N; k++){
        if (S[i] == 'c' && S[j] == 'w' && S[k] == 'w'){
          ans = min(ans, k - i + 1);
        }
      }
    }
  }
  if (ans == INF){
    cout << -1 << endl;
  } else {
    cout << ans << endl;
  }
}