#include <iostream>
#include <string>

void solve() {
    std::string s;
    std::cin >> s;

    int n = s.length();

    int ans = n + 1;
    for (int k = 0; k < n; ++k) {
        for (int j = 0; j < k; ++j) {
            for (int i = 0; i < j; ++i) {
                if (s[i] != 'c' ||
                    s[j] != 'w' ||
                    s[k] != 'w') continue;

                ans = std::min(ans, k - i + 1);
            }
        }
    }

    std::cout << (ans == n + 1 ? -1 : ans) << std::endl;
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}