#ifdef DEBUG_IS_VALID
#define DEB 1 
#define _LIBCPP_DEBUG 0
#else
#define DEB 0
#define NDEBUG
#endif

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

#define ALL(g) (g).begin(),(g).end()
#define REP(i, x, n) for(long long i = x; i < n; i++)
#define rep(i,n) REP(i,0,n)
#define RREP(i, x, n) for(long long i = x; i >= n; i--)
#define rrep(i, n) RREP(i,n,0)
#define pb push_back
#define fi first
#define se second
#pragma GCC optimize ("-O3")

using namespace std;

#define DUMPOUT cout
#define dump(...) if(DEB) DUMPOUT<<"  "<<#__VA_ARGS__<<" :["<<__LINE__<<":"<<__FUNCTION__<<"]"<<endl<<"    "; if(DEB) dump_func(__VA_ARGS__)
template<typename T1,typename T2>ostream& operator << (ostream& os, pair<T1,T2> p){cout << "(" << p.first << ", " << p.second << ")"; return os;}
template<typename T>ostream& operator << (ostream& os, vector<T>& vec) { os << "{"; for (int i = 0; i<vec.size(); i++) os << vec[i] << (i + 1 == vec.size() ? "" : ", "); os << "}"; return os; }
template<typename T>ostream& operator << (ostream& os, set<T>& st){cout << "{"; for(auto itr = st.begin(); itr != st.end(); itr++) cout << *itr << (next(itr)!=st.end() ? ", " : ""); cout << "}"; return os;}
template<typename T1,typename T2>ostream& operator << (ostream& os, map<T1,T2> mp){cout << "{"; for(auto itr = mp.begin(); itr != mp.end(); itr++) cout << "(" << (itr->first) << ", " << (itr->second) << ")" << (next(itr)!=mp.end() ? "," : ""); cout << "}"; return os; }

void dump_func(){DUMPOUT << endl;}
template <class Head, class... Tail>void dump_func(Head&& head, Tail&&... tail){ DUMPOUT << head; if (sizeof...(Tail) == 0) { DUMPOUT << " "; } else { DUMPOUT << ", "; } dump_func(std::move(tail)...);}
template<class T> inline bool chmax(T& a,T const& b){if(a>=b) return false; a=b; return true;}
template<class T> inline bool chmin(T& a,T const& b){if(a<=b) return false; a=b; return true;}

using Int = long long;
using ll = long long;
using P = pair<Int,Int>;
using vi = vector<Int>;
using vvi = vector<vi>;
using vp = vector<P>;
using vvp = vector<vp>;

const Int INF = (1<<30)-10;

class DynamicModInt {
  public:
  static int MOD;
  unsigned x; DynamicModInt() : x(0) { }
  DynamicModInt(signed sig) { x = sig < 0 ? sig % MOD + MOD : sig % MOD; }
  DynamicModInt(signed long long sig) { x = sig < 0 ? sig % MOD + MOD : sig % MOD; }
  int get() const { return (int)x; }
  DynamicModInt &operator+=(DynamicModInt that) { if ((x += that.x) >= MOD) x -= MOD; return *this; }
  DynamicModInt &operator-=(DynamicModInt that) { if ((x += MOD - that.x) >= MOD) x -= MOD; return *this; }
  DynamicModInt &operator*=(DynamicModInt that) { x = (unsigned long long)x * that.x % MOD; return *this; }
  DynamicModInt &operator/=(DynamicModInt that) { return *this *= that.inverse(); }
  DynamicModInt operator+(DynamicModInt that) const { return DynamicModInt(*this) += that; }
  DynamicModInt operator-(DynamicModInt that) const { return DynamicModInt(*this) -= that; }
  DynamicModInt operator*(DynamicModInt that) const { return DynamicModInt(*this) *= that; }
  DynamicModInt operator/(DynamicModInt that) const { return DynamicModInt(*this) /= that; }
  DynamicModInt inverse() const { long long a = x, b = MOD, u = 1, v = 0;
    while (b) { long long t = a / b; a -= t * b; std::swap(a, b); u -= t * v; std::swap(u, v); }
    return DynamicModInt(u); }
  bool operator==(DynamicModInt that) const { return x == that.x; }
  bool operator!=(DynamicModInt that) const { return x != that.x; }
  DynamicModInt operator-() const { DynamicModInt t; t.x = x == 0 ? 0 : MOD - x; return t; }
};
ostream& operator<<(ostream& st, const DynamicModInt a) { st << a.get(); return st; };
DynamicModInt operator^(DynamicModInt a, unsigned long long k) {
  DynamicModInt r = 1; while (k) { if (k & 1) r *= a; a *= a; k >>= 1; } return r; }
  // *より優先順位が高いため注意
int DynamicModInt::MOD;
void set_mod(signed mod){DynamicModInt::MOD = mod;}
using mint = DynamicModInt;

void solve(long long N, long long P, string S){
  Int ans = 0;
  if(P <= 500){
    vector<Int> ary(P), nxt;
    rep(i, N){
      dump(ary);
      Int ss = Int(S[i] - '0');
      ary[ss % P]++;
      ans += ary[0];
      nxt.clear();
      nxt.resize(P);
      rep(p, P){
        if(i == N-1) break;
        ss = Int(S[i+1] - '0');
        nxt[(p * 10 + ss) % P] += ary[p];
      }
      swap(ary, nxt);
    }
  }else{  
    set_mod(P);
    mint inv = mint(1) / mint(10);
    mint co = mint(1);
    vector<mint> a(N), s(N+1);
    rep(i, N){
      a[i] = mint(int(S[i]-'0')) * co;
      co *= inv;
    }
    rep(i, N+1) s[i+1] = s[i] + a[i];
    vector<Int> ary(P);
    rep(i, N+1){
      ans += ary[s[i].x];
      ary[s[i].x]++;
    }
  }
  cout << ans << endl;
}

int main(){
  std::cout << std::fixed << std::setprecision(15);
  long long N;
  scanf("%lld",&N);
  long long P;
  scanf("%lld",&P);
  string S;
  cin >> S;
  solve(N, P, S);
  return 0;
}


Measured memory_bytes: 2308