#include<bits/stdc++.h>
using namespace std;

int main() {
	ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	int N, P; cin >> N >> P;
	string S; cin >> S;
	long long ans = 0;
	if (P == 2 || P == 5) {
		for (int i = 0; i < N; i++) {
			int v = S[i] - '0';
			if (v % P == 0) {
				ans += i+1;
			}
		}
	} else {
		reverse(S.begin(), S.end());
		unordered_map<int, int> mp;
		mp[0] ++;
		int pref = 0;
		int pref10 = 1;
		for (char c  : S) {
			int v = c - '0';

			pref += v * pref10;
			pref %= P;

			ans += mp[pref]++;

			pref10 *= 10;
			pref10 %= P;
		}
	}
	cout << ans << '\n';

	return 0;
}
