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 Python (3.4.3) (judge verdict: Wrong Answer)

n,p=map(int,input().split())
s=input()

genL=[set() for i in range(n)]
ans=0


def ser(l,gL):
    global kari
    try:
        for gR in genL[l+len(str(gL))]:
            new=str(gL)+str(gR)
            if new not in genL[l]:
                kari.add(new)
                ser(l,new)
    except:
        pass




if p==2:
    for i in range(n):
        if int(s[i])%2==0:
            ans+=i+1
elif p==5:
    for i in range(n):
        if int(s[i])%5==0:
            ans+=i+1
else:
    pke=len(str(p))
    for i in range(pke+1):
        for l in range(n-i):
            num=int(s[l:l+i+1])
            if num%p==0:

                genL[l].add(str(num))


    for i in range(n):
        kari=set()
        for l in genL[i]:
            ser(i,l)

        for k in kari:
            genL[i].add(k)

    for i in genL:
        ans+=len(i)

print(ans)