#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<(n); i++)
char s[200005];
int n, p, dp, m=1;
long long cnt;
map<int,int> mp;
int main(){
	scanf("%d%d\n%s", &n, &p, s);
	mp[0]++;
	for(int i=n-1; i>=0; i--){
		(dp += m*(s[i]-'0')) %= p;
		mp[dp]++;
		(m *= 10) %= p;
		if(p == 2 && ((s[i]-'0')%2 == 0)) cnt += i+1;
		else if(p == 5 && ((s[i]-'0')%5 == 0)) cnt += i+1;
	}
	if(p != 2 && p != 5){
		for(auto it: mp) cnt += (long long)it.second * (it.second - 1) / 2;
	}
	printf("%lld\n", cnt);
}