#include <bits/stdc++.h>

using namespace std;

ifstream fin("asciimat.in");
ofstream fout("asciimat.out");

int a[302][702];
char s[3001];
int t, k, n, poz, lin = 0, m, lung, rez_t2, rez_maxx;

bitset <7> caracter;

void copiaza()
{
    int fin = poz + 6, poz1 = 6;
    for (; poz <= fin; ++poz)
    {
        a[n][poz] = caracter[poz1--];
    }
    poz = fin + 1;
}

int main()
{
    fin >> t;
    fin.ignore();
    fin.getline(s, 3000);
    char *p = strtok(s, " ");
    while (p != NULL)
    {
        lung = strlen(p);
        poz = 1;
        n++;
        if (7 * lung > m) m = 7 * lung;
        for (int i = 0; i < lung; ++i)
        {
            caracter = p[i];
            copiaza();
        }
        p = strtok(NULL, " ");
    }
    fin >> k;
    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
        {
            if (a[i][j]) a[i][j] = min(a[i - 1][j - 1], min(a[i - 1][j], a[i][j - 1])) + 1;
            if (a[i][j] > rez_maxx)
                rez_maxx = a[i][j];
        }
    }
    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
        {
            if (a[i][j] >= k) rez_t2++;
        }
    }
    if (t == 1)
        fout << rez_maxx;
    else
        fout << rez_t2;
    return 0;
}