#include<iostream>
#include<string>

using namespace std;

int main()
{
	string s;
	int min = 101, i, j, n, flags;
	cin >> s;
	n = s.length();
	for (i = 0; i < n; i++) {
		if (s[i] == 'c') {
			flags = 0;
			for (j = i; flags < 2 && j < n; j++) {
				if (s[j] == 'w') {
					flags++;
				}
			}
			if (flags == 2 && j - i < min) {
				min = j - i;
			}
		}
	}
	if (min == 101) {
		cout << -1 << endl;
	}
	else {
		cout << min << endl;
	}
	return 0;
}