#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>

using namespace std;

int main() {

    string S;
    cin >> S;
    int c = -1;
    int cw = -1;

    int N = S.size();
    int m = N;
    bool found = false;
    int ans = 1000;
    for (int i = 0; i < N; ++i) {

        if (S[i] == 'c') {
            c = i;
        } else if (S[i] == 'w') {
            if (cw != -1) {
                ans = min(ans, i - cw + 1);
            }
            if (c != -1) {
                cw = c;
            }
        }
    }

    if (ans == 1000) {
        cout << -1 << endl;
    } else {
        cout << ans << endl;
    }

    return 0;
}