#include<bits/stdc++.h>
using namespace std;

#define fastio 

#define ll long long
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define ld long double
#define forn(low,high,i) for(i = low; i < high; i++)
#define forrev(high,low,i) for(i = high; i >= low; i--)
#define all(v) v.begin(),v.end()
#define decimal_digits cout << fixed << setprecision(15);

string to_string(string s) { return '"' + s + '"';}
string to_string(char s) { return string(1, s);}
string to_string(const char* s) { return to_string((string) s);}
string to_string(bool b) { return (b ? "true" : "false");}
template <typename A> string to_string(A);
template <typename A, typename B>string to_string(pair<A, B> p) {return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";}
template <typename A> string to_string(A v) {bool f = 1; string r = "{"; for (const auto &x : v) {if (!f)r += ", "; f = 0; r += to_string(x);} return r + "}";}
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) {cerr << " " << to_string(H); debug_out(T...);}
#define pr(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

const int inf = 1e9;
const long long INF = 1e18;
const int mod = 1e9 + 7;
const int bit32 = log2(inf) + 3;
const int bit64 = log2(INF) + 3;

inline int add(long long a, long long b){a += b; if(a >= mod) a -= mod; return a;}
inline int sub(long long a, long long b){a -= b; if(a < 0) a += mod; return a;}
inline int mul(long long a, long long b){a %= mod; b %= mod; return (int)((long long) a * b % mod);}
inline int modexpo(long long a, long long b){int res = 1; while(b > 0){ if(b & 1) res = mul(res, a); a = mul(a, a); b /= 2;} return res;}
inline int divide(long long a, long long b){return mul(a, modexpo(b, mod - 2));}
inline int inv(long long a){return modexpo(a, mod - 2);}

clock_t time_p = clock();

void ktj(){
  time_p = clock() - time_p;
  cerr << "Time elapsed : " << (float)(time_p)/CLOCKS_PER_SEC << "\n";
}

void pre(){ // Reset each global variable (esp. for graphs)
  
}

const int N = 2e5 + 5;

int mExp[N];

void pre(int n, int p){
  mExp[0] = 1;
  for(int i = 1; i <= n; i++){
    mExp[i] = ((mExp[i - 1] % p) * (10 % p)) % p;
  }
}

void solve(){
  int n, p, i, j, k;
  string s; cin >> n >> p >> s;
  s = '$' + s;
  pre(n, p);
  map<int, int> m;
  int pref[n];
  int sum = 0;

  if(p == 2){
    long long ans = 0;
    for(i = 1; i <= n; i++){
      if((s[i] - '0') % 2 == 0)
        ans += i;
    }
    cout << ans << '\n'; return;
  }

  if(p == 5){
    long long ans = 0;
    for(i = 1; i <= n; i++){
      if((s[i] - '0') % 5 == 0)
        ans += i;
    }
    cout << ans << '\n'; return;
  }

  for(i = n; i >= 1; i--){
    sum = (sum % p + (((s[i] - '0') % p) * mExp[n - i] % p) % p) % p;
    pref[i] = sum;
    m[sum] += 1;
  }
  long long ans = m[0];
  sum = 0;
  for(i = n; i >= 1; i--){
    m[pref[i]] -= 1;
    sum = (sum % p + ((s[i] - '0') % p * mExp[n - i] % p) % p) % p;
    ans += m[sum];
  }
  cout << ans << '\n';
}

int main(){
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);cout.tie(NULL); 

  pre();

  int t = 1, T = t;
  // cin >> t;
  while(t--){
    // cout << "Case #" << T - t << ": ";
    solve();
  }

  ktj();
}


Measured memory_bytes: 2512