#include <algorithm>
#include <climits>
#include <iostream>
#include <string>
#include <vector>
using namespace std;

bool is_cww(string s) {
	int N = s.length(), j = 0;
	string t = "cww";
	for (int i = 0; i < N; i++)
		if (j < 3 && s[i] == t[j])
			j++;
	return j == 3;
}

int main() {
	string s; cin >> s;
	int N = s.length();
	int mi = INT_MAX;
	for (int l = 0; l <= N; l++)
		for (int r = l; r <= N; r++)
			if (is_cww(s.substr(l, r - l)))
				mi = min(mi, r - l);
	if (mi == INT_MAX) mi = -1;
	cout << mi << endl;
}