import java.util.*;
import java.util.Map.Entry;

import javax.swing.text.Segment;
import javax.xml.ws.WebEndpoint;

import java.io.*;
import java.lang.reflect.Array;
import java.math.BigInteger;

import static java.lang.Math.*;
import static java.util.Arrays.*;
import static java.util.Collections.*;

public class Main implements Runnable
{
//    static int dx[]={-1,0,1,0};
//    static int dy[]={0,-1,0,1};
    static long mod=1000000007;
    
    public static void main(String[] args) {        
        new Thread(null, new Main(), "", 200 * 1024 * 1024).start();        
    }

    public void run() {
        Reader sc = new Reader(System.in);
        PrintWriter out=new PrintWriter(System.out);

        int n=sc.nextInt();
        int p=sc.nextInt();
        char c[]=sc.getCharSet();
        int r[]=new int[p];
//        r[0]=1;
        long t=1,a=0,s=0;
        if(p==2) {
            for (int i = 0,v,w; i < c.length; i++) {
    			v=n-i-1;
    			w=(c[v]-'0')%2;
    			if(w==0) {
    				a+=n-i;
    			}
            }
        }
        else if(p==5) {
        	long ng=0;
            for (int i = 0,v,w; i < c.length; i++) {
    			v=n-i-1;
    			w=(c[v]-'0');
    			if(w==0 || w==5) {
    				a+=n-i;
    				ng++;
    			}
            }        	
        }
        else
        for (int i = 0,v,w,x; i < c.length; i++) {
			v=n-i-1;
			w=(c[v]-'0');
			s+=t*w%p;
			s%=p;
			x=(int)s;
			a+=r[x];
			if(x==0)a++;
			r[x]++;
			t*=10;
			t%=p;
		}
        
        out.println(a);
     	out.flush();
    }
    
    static void ret(String ans) {
    	System.out.println(ans);
    	System.exit(0);
    }

    static void ret(long ans) {
    	System.out.println(ans);
    	System.exit(0);
    }
    
    static boolean validpos(int x,int y,int r, int c){
        return x<r && 0<=x && y<c && 0<=y;
    }

    static void db(Object... os){
        System.err.println(Arrays.deepToString(os));
    }
}

//class P {
//	int x,y; double d;
//	P(int  x, int y, double d) {
//	  this.x=x;
//	  this.y=y;
//	  this.d=d;
//	}
//}


class P implements Comparable<P>{
    int p,h,f; long m;
    P(int p,int h, int f, long m) {
    	this.p=p;
    	this.h=h;
    	this.f=f;
    	this.m=m;
    }

    public int compareTo(P p){
    	if(this.p==p.p) {
    		if(this.f==-1) return 1;
    		return -1;
    	}
        return this.p-p.p;
    }
}

class Reader
{ 
    private BufferedReader x;
    private StringTokenizer st;
    
    public Reader(InputStream in)
    {
        x = new BufferedReader(new InputStreamReader(in));
        st = null;
    }
    public String nextString()
    {
        while( st==null || !st.hasMoreTokens() )
			try {
				st = new StringTokenizer(x.readLine());
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
        return st.nextToken();
    }
    public int nextInt()
    {
        return Integer.parseInt(nextString());
    }
    public int[] nextIntArray(int size) {
        int r[] = new int[size];
        for (int i = 0; i < size; i++) {
            r[i] = this.nextInt(); 
        }
        return r;
    }
    public long[] nextLongArray(int size) {
        long r[] = new long[size];
        for (int i = 0; i < size; i++) {
            r[i] = this.nextLong(); 
        }
        return r;
    }
    public char[] getCharSet() {
        return this.nextString().toCharArray();
    }    
    public long nextLong()
    {
        return Long.parseLong(nextString());
    }
    public double nextDouble() throws IOException
    {
        return Double.parseDouble(nextString());
    }
}


Measured memory_bytes: 28416