/* -*- coding: utf-8 -*-
 *
 * 345.cc: No.345 最小チワワ問題 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int INF = 1 << 30;

/* typedef */

/* global variables */

/* subroutines */

/* main */

int main() {
  string s;
  cin >> s;

  int n = s.size();
  int minl = INF;

  for (int i = 0; i < n; i++)
    if (s[i] == 'c') {
      int wn = 0;
      for (int j = i + 1; j < n; j++)
	if (s[j] == 'w') {
	  wn++;
	  if (wn >= 2) {
	    int l = j - i + 1;
	    if (minl > l) minl = l;
	    break;
	  }
	}
    }

  printf("%d\n", (minl >= INF) ? -1 : minl);
  return 0;
}