#include <iostream>
#include <string>

using namespace std;
#define INF 1000
#define MIN(a,b) ((a)<(b)?(a):(b))
#define FOR(i,a,b) for (int i=(a);i<(b);i++)

int main()
{
	int n, len = INF;
	string s;
	cin >> s;

	n = s.size();
	FOR(i, 0, n){		if (s[i] == 'c') {
	FOR(j, i + 1, n) {	if (s[j] == 'w') {
	FOR(k, j + 1, n) {	if (s[k] == 'w') {
		len = MIN(k - i + 1, len);
	}}}}}}

	cout << (len == INF ? -1 : len) << endl;
	return 0;
}