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

using namespace std;

string s;
string cww = "cww";
const int INF = 1e6;
int check(int p) {
//    cout << endl;
    int x = 0;
    for(int i = p; i < s.size(); i++) {
//        cout << s[i] << endl;
        if(s[i] == cww[x]) x++;
        if(p != i and s[i] == 'c') return INF;
        if(x == cww.size()) {
            //cout << i - p + 1 << endl;
            return i - p + 1;
        }
    }
    return INF;
}

int main() {
    cin >> s;
    int ans = INF;
    for(int i = 0; i < s.size(); i++) {
        if(s[i] != cww[0]) continue;
        ans = min(ans, check(i));
    }
    if(ans == INF) ans = -1;
    cout << ans << endl;
}