#include <bits/stdc++.h>

using namespace std;

int main() {
    int n;
    cin >> n;
    vector<string> s(n);
    for (int i = 0; i < n; i++) {
        cin >> s[i];
    }
    int m, x, d;
    cin >> m >> x >> d;

    int sum = 0;
    for (int k = 1; k <= m; k++) {
        int i, j;
        i = (x / (n - 1));
        j = (x % (n - 1));
        if (i > j) {
            swap(i, j);
        } else {
            j++;
        }
        x = (x + d) % (n * (n - 1));

        // cout << "i: " << i << " j: " << j << " x: " << x << endl;
        // cout << s[i].length() << " " << s[j].length() << endl;
        int len = min(s[i].length(), s[j].length());
        for (int l = 0; l < len; l++) {
            if (s[i][l] == s[j][l]) {
                sum++;
            } else {
                break;
            }
        }
    }

    cout << sum << endl;

    return 0;
}