#include <iostream>
#include <algorithm>
#include <vector>
#include<string>

using namespace std;
int main(){
	string s;
	bool flag = false;
	int cnt = 0,a=0,co=0;
	int minv=-1;
	cin >> s;
	for (int i = 0; i < s.size(); i++) {
		if (s[i] == 'c') {
			flag = true;
		}

		if (flag) {
			cnt++;
			if (s[i] == 'w') {
				a++;
				if (a == 2) {
					flag = false;
					co++;
					if (co == 1) {
						minv = cnt;
					}else{
						minv = min(minv, cnt);
					}
				}
			}
		}
	}
	cout << minv << endl;
}