#include <algorithm>
#include <complex>
#include <cstdlib>
#include <ctime>
#include <time.h>
#include <iomanip>
#include <iostream>
#include <map>
#include <math.h>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>

using namespace std;
#define SAY_YES cout << "YES" << endl;
#define SAY_Yes cout << "Yes" << endl;
#define SAY_NO cout << "NO" << endl;
#define SAY_No cout << "No" << endl;
#define IFYES(TRUE_OR_FALSE)   \
    if (TRUE_OR_FALSE)         \
    {                          \
        cout << "YES" << endl; \
    }                          \
    else                       \
    {                          \
        cout << "NO" << endl;  \
    }
#define IFYes(TRUE_OR_FALSE)   \
    if (TRUE_OR_FALSE)         \
    {                          \
        cout << "Yes" << endl; \
    }                          \
    else                       \
    {                          \
        cout << "No" << endl;  \
    }
#define IFyes(TRUE_OR_FALSE)   \
    if (TRUE_OR_FALSE)         \
    {                          \
        cout << "yes" << endl; \
    }                          \
    else                       \
    {                          \
        cout << "no" << endl;  \
    }
#define DEBUG_OUTPUT_ARRAY(XXX, ONE)                            \
    for (int i = 0; i < (ONE); i++)                             \
    {                                                           \
        cout << "DEBUG: i = " << i << " -> " << XXX[i] << endl; \
    }
#define DEBUG_OUTPUT_ARRAY2(XXX, ONE, TWO)                             \
    for (int i = 0; i < (ONE); i++)                                    \
    {                                                                  \
        cout << "<<< i = " << i << " >>>" << endl;                     \
        for (int j = 0; j < (TWO); j++)                                \
        {                                                              \
            cout << "DEBUG: j = " << j << " -> " << XXX[i][j] << endl; \
        }                                                              \
    }
#define DEBUG_OUTPUT_ARRAY2_BOX(XXX, ONE, TWO) \
    for (int i = 0; i < (ONE); i++)            \
    {                                          \
        cout << i << "  ";                     \
        for (int j = 0; j < (TWO); j++)        \
        {                                      \
            cout << XXX[i][j] << " ";          \
        }                                      \
        cout << endl;                          \
    }

typedef pair<long long int, long long int> pll;


const long long int mod = 998244353;
const long long int INF = 1e18;




//累乗(繰り返し2乗法)　aのb乗(mod)を求める。
class Ruizyou{
    public:
    long long int rui(long long int a, long long int b, long long mod) {
        int memo[65] = {};
        long long int A[65] = {};
        long long int tmp = 1;
        for (int i = 0; i < 65; i++) {
            memo[i] = b % 2;
            b /= 2;
        }

        A[0] = a;
        A[0] %= mod;

        for (int i = 1; i < 65; i++) {
            A[i] = A[i - 1] * A[i - 1];
            A[i] %= mod;
        }
        for (int i = 0; i < 65; i++) {
            if (memo[i] == 1) {
                tmp *= A[i];
                tmp %= mod;
            }
        }
        tmp %= mod;
        return tmp;
    }
};

long long int N,P,amari[200040]={},amari2[200040],now=0,res=0;
string S;
int main()
{
    cout << fixed << setprecision(18);
    cin>>N>>P>>S;
    Ruizyou rui;
    if(P==2||P==5){
        for(long long int i = N-1; i >=0; i--){
            if((S[i]-'0')%P==0){res+=i+1;}
        
        }
    }else{

        for(long long int i = N-1; i >=0; i--){
            now=now+(S[i]-'0')*rui.rui(10,N-i-1,P);
            now%=P;
            res+=amari[now];
            if(now==0){res++;}
            amari[now]++;
        }
    }
    cout<<res<<endl;
}


Measured memory_bytes: 644