#include <iostream>

int main() {
    std::string s;
    int min = 101, w = 0, w2 = 0, flag = 0;
    std::cin >> s;
    for (int i = s.length() - 1; i >= 0; i--)
        if (s[i] == 'w') {
            if (!w) w = i;
            else {
                if (flag) w = w2;
                else flag = 1;
                w2 = i;
            }
        } else if (flag && s[i] == 'c') min = w - i + 1 < min ? w - i + 1 : min;

    std::cout << (min != 101 ? min : -1) << std::endl;
    return 0;
}