#include <bits/stdc++.h>
using namespace std;
#define N 200005
#define ll long long
int n,m,pw[N],dp[N],bc[N];ll ans;char a[N];
int main()
{
	scanf("%d %d %s",&n,&m,a+1);
	pw[0]=1;for(int i=1;i<=n;++i) pw[i]=pw[i-1]*10%m;
	if(m==2)
	{
		for(int i=1;i<=n;++i) if(!((a[i]&15)%2)) ans+=i;
		printf("%lld\n",ans);return 0;
	}
	if(m==5)
	{
		for(int i=1;i<=n;++i) if(!((a[i]&15)%5)) ans+=i;
		printf("%lld\n",ans);return 0;
	}bc[0]=1;
	for(int i=1;i<=n;++i)
	{
		dp[i]=(dp[i-1]*10+(a[i]&15))%m;
		ans+=bc[dp[i]*pw[n-i]%m];++bc[dp[i]*pw[n-i]%m];
	}printf("%lld\n",ans);return 0;
}