#include <bits/stdc++.h>

using namespace std;

int main() {

  string S; cin >> S;
  int min = 1e9;
  for(int i=0; i<S.size(); i++) {
    if(S[i] != 'c') continue;
    int cnt = 0;
    int cc = 1;
    for(int k=i+1; k<S.size(); k++) {
      if(S[k] == 'w') cnt++;
      cc++;
      if(cnt == 2) break;
    }
    if(cnt == 2) {
      min = std::min(min, cc);
    }
  }

  cout << (min == 1e9 ? -1 : min) << endl;

  return 0;
}