#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define pii pair<int,int>
#define pp pair<pair<ll, ll>,pair<ll, ll>>
#define pll pair<ll,ll>
#define pdd pair<double,double>
#define vii vector<int>
#define vll vector<ll>
#define mat vector<vector<ll>>
#define lb lower_bound
#define ub upper_bound
#define pb push_back
#define eb emplace_back
#define fi first
#define sc second
#define rep(i,n) for(ll i=0;i<n;i++)
#define rep2(i,a,b) for(ll i=a;i<b;i++)
#define repr(i,n) for(ll i=n-1;i>=0;i--)
#define all(x) x.begin(),x.end()
#define sz(x) (ll) (x).size()
#define pq priority_queue<ll>
#define pqg priority_queue<ll,vector<ll>,greater<ll>>
#define LB(v,x) (lower_bound(v.begin(),v.end(),x)-v.begin())
#define UB(v,x) (upper_bound(v.begin(),v.end(),x)-v.begin())
#define ERASE(v) sort(v.begin(),v.end());v.erase(unique(v.begin(),v.end()),v.end())
#define int ll
// #define ll int
using namespace std;
const ll INF = (1 << 30 ) - 1;
const ll LLINF = (1LL << 60LL);
const ll MOD = 1000000007;
const ll mod = 998244353;
const ll MAX = 1100000;
const double pi = acos(-1);
const double eps = 1e-10;
ll dx[8] ={1,0,-1,0,1,-1,1,-1};
ll dy[8] ={0,1,0,-1,1,-1,-1,1};
 
template<class T> 
inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> 
inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
 
struct Timer{
    chrono::system_clock::time_point start, end;
    Timer(){ start = chrono::system_clock::now(); }
    ~Timer(){
        end = chrono::system_clock::now();
        auto msec = chrono::duration_cast<chrono::milliseconds>(end - start).count();
        cerr<<"time : "<<msec<<" ms"<<endl;
    }
};


void solve(){
    ll n,p;
    cin>>n>>p;
    string s;
    cin>>s;
    ll sum[200010]={};
    ll m[200010]={};
    m[0]=1;
    rep(i,n+1){
        m[i+1]=m[i]*10%p;
    }
    reverse(all(s));
    rep(i,n){
        sum[i+1]=sum[i]+(s[i]-'0')*m[i]%p;
        sum[i+1]%=p;
    }
    // rep(i,n+1){
    //     cout<<sum[i]<<" ";
    // }
    // cout<<endl;
    if(p==2){
        ll ans=0;
        rep(i,n){
            if((s[i]-'0')%2==0){
                ans+=n-i;
            }
        }
        cout<<ans<<endl;
        return;
    }
    if(p==5){
        ll ans=0;
        rep(i,n){
            if((s[i]-'0')%5==0){
                ans+=n-i;
            }
        }
        cout<<ans<<endl;
        return;
    }
    ll ans=0;
    ll x[100010]={};
    repr(i,n+1){
        ans+=x[sum[i]];
        x[sum[i]]++;
        // cout<<ans<<"FG"<<x[sum[i]]<<endl;
    }
    cout<<ans<<endl;
    // ans=0;
    // rep(i,n){
    //     rep2(j,i+1,n){
    //         string t=s.substr(i,j-i);
    //         // cout<<t<<" ";
    //         ll y=stoll(t);
    //         if(y%p==0){
    //             cout<<t<<" "<<i<<" "<<j<<endl;
    //             ans++;
    //         }
    //         // else cout<<endl;
    //     }
    // }

    // cout<<ans<<"%%%$"<<endl;
}

 
signed main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(15);
    // Timer TM;
     
    solve();


    return 0;
}

Measured memory_bytes: 4500