#include <bits/stdc++.h>
using namespace std;

bool is_cww (const string &s) {
    bool c = false, w = false, ww = false;
    for (const char &ch : s) {
        if (!c and !w and !ww) {
            if (ch == 'c') c = true;
        } else if (c and !w and !ww) {
            if (ch == 'w') w = true;
        } else if (c and w and !ww) {
            if (ch == 'w') ww = true;
        }
    }
    return (c and w and ww);
}

int main() {
    string s;
    cin >> s;
    
    int ans = 111;
    for (int i = 0; i < s.length(); i++) {
        for (int len = 1; i + len <= s.length(); len++) {
            if (is_cww(s.substr(i, len))) ans = min(ans, len);
        }
    }
    
    if (ans == 111) ans = -1;
    cout << ans << '\n';
    return 0;
}