#include <bits/stdc++.h>
using namespace std;
char t[33], s[2020];
int n, k, ans;
#define ull unsigned long long
set<ull> st;

int main() {
	scanf("%s%s%d", s, t, &k);
	n = strlen(s);
	for (int i = 0; i < n; i++) {
		ull h = 0;
		for (int j = i, c = 0; j < n; j++) {
			if (t[s[j] - 'a'] == '0')
				c++;
			if (c > k)
				break;
			h = h * 31 + s[j] - 'a' + 1;
			st.insert(h);
		}
	}
	printf("%d\n", st.size());
	return 0;
}