import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    int ans = 1000;
    for(int i = 0; i < s.length(); i++) {
      if(s.charAt(i) == 'c') {
        int len = 1000;
        int count = 0;
        for(int j = i + 1; j < s.length(); j++) {
          if(s.charAt(j) == 'w') count++;
          if(count == 2) {
            len = j - i + 1;
            break;
          }
        }
        ans = Math.min(ans, len);
      }
    }
    if(ans == 1000) ans = -1;
    System.out.println(ans);
  }
}