struct node{
    int is_end, bad_let;
    node* next[26];
    node(int bad_len) : bad_let(bad_let), is_end(0) {
        memset(next, 0, sizeof(next));
    }
};
typedef node * pnode;

int bad[30];
void add_string(pnode v, string &s) {
    forn(i, (int)s.size()) {
        if (!v->next[s[i]])
            v->next[s[i]] = new node(bad[s[i]]);
        v = v->next[s[i]];
    }
    v->is_end = 1;
    return;
}

int dfs(pnode v, int k, int sum = 0) {
    if (!v)
        return 0;
    sum += v->bad_let;
    if (sum > k)
        return 0;
    int ans = 1;
    forn(i, 26) {
        ans += dfs(v->next[i], k, sum);
    return ans;
}

void solve() {
    string s, a;
    int k;
    cin >> s >> a >> k;
    forn(i, (int)a.size())
        bad[i] = (a[i] - '0');
    int n = (int)s.size();
    forn(i, n)
        s[i] -= 'a';
    pnode root = new node(0);
    forn(i, n) {
        string cur;
        for (int j = i; j < n; ++j)
            cur += s[j];
        add_string(root, cur);
    }
    cout << dfs(root, k) - 1;
}

int main() {
#ifdef  _DEBUG
    freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout);
#endif
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    solve();
}