// No.345 最小チワワ問題
// https://yukicoder.me/problems/no/345
// WA
using namespace std;

#include <iostream>
#include <regex>

long solve(string &S);

int main() {
    string S;
    cin >> S;
    long ans = solve(S);
    cout << ans << endl;
}


long solve(string &S) {
    const long NOT_FOUND = 9999999;
    long min_size = NOT_FOUND;
    regex rx(R"(c.*?w.*?w)");

    for (auto i = 0; i < S.size()-1; i++) {
        sregex_iterator it(S.begin()+i, S.end(), rx);
        sregex_iterator end;
        while (it != end) {
            if (it->str().size() < min_size)
                min_size = it->str().size();
            it++;
        }
    }
    if (min_size == NOT_FOUND)
        return -1;
    return min_size;
}