#include <iostream>

int main() {
    std::string s;
    int max = 0, flag = 0, cnt = 0;
    std::cin >> s;
    for (int i = 0; i < s.length(); i++) {
        if (!flag && s[i] == 'c') flag = 1;
        else if (flag && s[i] == 'w') flag += 1;
        if (flag) cnt += 1;
        if (flag == 3) {
            max = max < cnt ? cnt : max;
            flag = 0;
            cnt = 0;
        }
    }
    std::cout << (max ? max : -1) << std::endl;
    return 0;
}