#include <algorithm>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <iostream>
#include <map>
#include <ostream>
#include <queue>
#include <stack>
#include <string>
#include <vector>
#define INF 1000000000
#define rep(i,a,b) for (int i=(a);i<(b);i++)
#define rev(i,a,b) for (int i=(a)-1;i>=b;i--)
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef queue<int> qi;
typedef vector<int> vi;
typedef vector<string> vs;
int dx[4] = { 0, 1, 0, -1 };
int dy[4] = { 1, 0, -1, 0 };

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

  string s;
  cin >> s;
  int ans = INF;
  rep(i,0,s.size()) {
    if(s[i] == 'c') {
      bool flag = false;
      rep(j,i+1,s.size()) {
        if(s[j] == 'w') {
          if(!flag) flag = true;
          else {
            ans = min(ans, j-i+1);
            break;
          }
        }
      }
    }
  }

  if(ans == INF) cout << "-1" << endl;
  else cout << ans << endl;
	return 0;
}