Problem:
Score : 500 points

Problem Statement

Takahashi has a string S of length N consisting of digits from 0 through 9.

He loves the prime number P. He wants to know how many non-empty (contiguous) substrings of S - there are N \times (N + 1) / 2 of them - are divisible by P when regarded as integers written in base ten.

Here substrings starting with a 0 also count, and substrings originated from different positions in S are distinguished, even if they are equal as strings or integers.

Compute this count to help Takahashi.

Constraints

1 \leq N \leq 2 \times 10^5

S consists of digits.

|S| = N

2 \leq P \leq 10000

P is a prime number.

Input

Input is given from Standard Input in the following format:

N P
S

Output

Print the number of non-empty (contiguous) substrings of S that are divisible by P when regarded as an integer written in base ten.

Sample Input 1

4 3
3543

Sample Output 1

6

Here S = 3543. There are ten non-empty (contiguous) substrings of S:

3: divisible by 3.

35: not divisible by 3.

354: divisible by 3.

3543: divisible by 3.

5: not divisible by 3.

54: divisible by 3.

543: divisible by 3.

4: not divisible by 3.

43: not divisible by 3.

3: divisible by 3.

Six of these are divisible by 3, so print 6.

Sample Input 2

4 2
2020

Sample Output 2

10

Here S = 2020. There are ten non-empty (contiguous) substrings of S, all of which are divisible by 2, so print 10.

Note that substrings beginning with a 0 also count.

Sample Input 3

20 11
33883322005544116655

Sample Output 3

68

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<bits/stdc++.h>

using namespace std;

typedef short sho;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef double db;
typedef string str;

typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ld,ld> pld;

typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<ld> vd;
typedef vector<str> vs;
typedef vector<pii> vpi;
typedef vector<pll> vpl;
typedef vector<pld> vpd;

#define STDIO
#define mp make_pair
#define FF first
#define SS second
#define sz(x) (int)x.size()
#define begin(x) (x).begin()
#define end(x) (x).end()
#define rbegin(x) (x).rbegin()
#define rend(x) (x).rend()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pf push_front
#define pb push_back
#define pp push
#define lb lower_bound
#define ub upper_bound

inline void checkmin(int &x, int y) {
	x = min(x, y);
}
inline void checkmax(int &x, int y) {
	x = max(x, y);
}

int n, p;
str s;

int main() {
#ifndef STDIO
	freopen("input.txt","r",stdin);
	freopen("output.txt","w",stdout);
#endif
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	/* start code */
	cin>>n>>p>>s;
	ll ans = 0;
	for(int i = 0; i < n; i++) {
		for(int len = 1; i + len - 1 < n; len++) {
			str t = s.substr(i, len);
			int inte = atoi(t.c_str());
			if(inte % p == 0) {
				ans++;
			}
		}
	}
	cout<<ans<<endl;
	/* end code */
	return 0;
}