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

using namespace std;

int main()
{
    string s;
    cin >> s;

    string tmp[100];
    int t = 0;
    for(int i = 0; i < s.length(); i++) {
        if (s[i] == 'c') {
            int cntw = 0;
            for (int j = i; j < s.length(); j++) {
                if (s[j] == 'w') cntw++;
                if (cntw == 2) {
                    tmp[t++] = s.substr(i,j - i + 1);
                    break;
                }
            }
        }
    }

    int ans = 110;
    for (int i = 0; i < 100; i++) {
        // cout << tmp[i].length() << " ";
        t = tmp[i].length();
        ans = !t ? ans : min(ans, t);
    }
    cout << (ans == 110 ? -1 : ans) << endl;

    return 0;
}