#include <bits/stdc++.h> 
#define lowbit(x) x&(-x)
using namespace std;
typedef long long ll;
const int N = 1e4+5;
const int M = 2e3;

int num[N];

int main(){
	int n,p;
	ll ans = 0;
	string s;
	scanf("%d%d",&n,&p);
	cin >> s;
	
	if(p == 2 || p == 5){
		for(int i = 0;i < n;++i){
			if((s[i]-'0') % p == 0) ans += i+1;
		}
	}
	else{
		int last = 0,base = 1;num[0]++;
		for(int i = n-1;i >= 0;--i){
			int t = (s[i]-'0')%p*base%p;
			(base *= 10) %= p;
			(last += t) %= p;
			ans += num[last];
			num[last]++;
		}
	}
	printf("%lld\n",ans);
    return 0;
}