#ifdef _MSC_VER
#include "stdc++.h"
#endif
#ifdef __GNUC__
#include<bits/stdc++.h>
#endif
using namespace std;

using ll = long long;

//constant
const double EPS = 1e-10;

#define REP(i, n) for (ll i = 0; i < n; i++)
#define FOR(i, s, e) for (ll i = s; i < e; i++)
#define ALL(x) (x).begin(),(x).end()
#define RALL(x) (x).rbegin(), (x).rend()

//debug
#define DUMP(x)  cerr << #x << " = " << (x) << endl;
#define DEBUG(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << endl;

// vector
//template<typename T> vector<vector<T>> vv(ll H, ll W, T v) { return vector<vector<T>> vec(H, vector<T>(W, v)); }

// view vector
template<typename T> void view(T e) { cout << e << endl; }
template<typename T> void view(const vector<T>& v) { for (const auto& e : v) { cout << e << " "; } cout << endl; }
template<typename T> void view(const vector<vector<T> >& vv) { for (const auto& v : vv) { view(v); } }

// DP
template<class T>bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }


ll MOD;
struct Mint {
    ll v;
    ll _mod;
    Mint() : v(0) {}
    Mint(signed v, ll _mod = MOD) : v(v), _mod(_mod) {}
    Mint(ll t, ll _mod = MOD) : _mod(_mod) {
        v = t % _mod;
        if (v < 0)
            v += _mod;
    }
 
    Mint pow(ll k) {
        Mint res(1), tmp(v);
        while (k) {
            if (k & 1)
                res *= tmp;
            tmp *= tmp;
            k >>= 1;
        }
        return res;
    }
    static Mint add_identity() { return Mint(0); }
    static Mint mul_identity() { return Mint(1); }
    Mint inv() { return pow(_mod - 2); }
 
    Mint& operator+=(Mint a) {
        v += a.v;
        if (v >= _mod)
            v -= _mod;
        return *this;
    }
    Mint& operator-=(Mint a) {
        v += _mod - a.v;
        if (v >= _mod)
            v -= _mod;
        return *this;
    }
    Mint& operator*=(Mint a) {
        v = v * a.v % _mod;
        return *this;
    }
    Mint& operator/=(Mint a) { return (*this) *= a.inv(); }
 
    Mint operator+(Mint a) const { return Mint(v) += a; };
    Mint operator-(Mint a) const { return Mint(v) -= a; };
    Mint operator*(Mint a) const { return Mint(v) *= a; };
    Mint operator/(Mint a) const { return Mint(v) /= a; };
 
    Mint operator-() const { return v ? Mint(_mod - v) : Mint(v); }
 
    bool operator==(const Mint a) const { return v == a.v; }
    bool operator!=(const Mint a) const { return v != a.v; }
    bool operator<(const Mint a) const { return v < a.v; }
};
ostream& operator<<(ostream& os, Mint m) { return os << m.v; }
 
ll nCk(ll n, int k) {
    ll ret = 1;
    for (int i = n; i > n - k; --i) {
        ret *= i;
    }
    for (int i = 1; i <= k; ++i) {
        ret /= i;
    }
    return ret;
}

// ***************************************


int main(){

    ll N, P;
    cin >> N >> P;
    string S;
    cin >> S;

    reverse(ALL(S));

    if (P == 2 || P == 5){
        ll ans = 0;
        REP(i, N){ if ((S[i] - '0') % P == 0) ans += (N - i); }
        std::cout << ans << endl;
        return 0;
    }

    MOD = P;
    vector<ll> cnt(P, 0);
    cnt[0] = 1;
    Mint cur(0, P);
    REP(i, N){
        cur += Mint(S[i] - '0') * Mint(10).pow(i);
        cnt[cur.v] ++;
    }
    ll ans = 0;
    for(auto& x: cnt){
        ans = ans + nCk(x, 2);
    }
    std::cout << ans << endl;

    return 0;
}


Measured memory_bytes: 640