#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <iomanip>
#include <cmath>
#include <functional>
using namespace std;
#define diff(x,y) ((x > y) ? (x - y) : (y - x))
#define us(x) (x > 0) ? x : x * -1

int main() {
	int min = 1000;
	string str;
	cin >> str;
	if (str.size() < 3) {
		cout << -1 << endl;
		return 0;
	}
	for (int i = 0; i < str.size() - 2; i++) {
		if (str[i] == 'c'){
			int w = 0;
			for (int j = 1;i + j < str.size(); j++) {
				if (str[i + j] == 'w')	w++;
				if (w == 2) {
					if (j < min)	min = j;
					goto A;
				}
			}
		}
		A:;
	}
	if (min != 1000)	cout << min + 1 << endl;
	else				cout << -1 << endl;
	return 0;
}