#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <algorithm>
//---------------------------
using namespace std;
//---------------------------
#define REP(i,n) for(int i = 0; i < (n); i++)
#define P(x) cout << (x) << "\n"
//---------------------------


int main(){
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);



  string s;cin >> s;
  int n = s.size();
  int ans = 101;
  for (int i = 0; i < n; i++) {
    if (s[i] == 'c') {
      for (int j = i+1; j < n; j++) {
        if (s[j] == 'w') {
          for (int k = j+1; k < n; k++) {
            if (s[k] == 'w') {
              ans = min(k-i+1,ans);
            }
          }
        }
      }
    }
  }
  if (ans == 101) {
    cout << -1 << "\n";
  }else{
    cout << ans << "\n";
  }
  return 0;
}