import sys
from itertools import combinations, permutations, product, combinations_with_replacement, accumulate
from heapq import heapify, heappop, heappush, heappushpop
from bisect import bisect_left, bisect_right
from collections import Counter, defaultdict
from math import sqrt, log, floor, ceil, factorial, cos, sin, pi, gcd
from collections import deque
sys.setrecursionlimit(10**5)
input = sys.stdin.readline
INF = float('inf')
LINF = 2**63-1
NIL = -LINF
MOD = 10**9+7
MGN = 4
def II(): return int(input())
def IF(): return float(input())
def IS(): return input().replace('\n', '')
def ILCI(n: int): return [II() for _ in range(n)]
def ILCF(n: int): return [IF() for _ in range(n)]
def ILI(): return list(map(int, input().split()))
def ILLI(n: int): return [[int(j) for j in input().split()] for i in range(n)]
def ILF(): return list(map(float, input().split()))
def ILLF(n: int): return [[float(j) for j in input().split()] for i in range(n)]
def LTOS(lst: list, sep: str = ' '): return sep.join(map(str, lst))
def DEC(lst: list): return list(map(lambda x: x-1, lst))
def INC(lst: list): return list(map(lambda x: x+1, lst))


def stoli(s, sep = ''):
    """ 文字列と区切り文字(列)を受け取り、
    整数のリストにして返す """
    if sep == None or sep == '':
        return list(map(int, list(s)))

    ls = []
    for e in s.split(sep):
        if e == None or e == '':
            continue
        else:
            ls.append(e)

    return list(map(int, ls))


def main():
    N, P = ILI()
    S = IS()

    d = stoli(S)
    
    d.reverse()

    if 10%P == 0:
        ans = 0
        for l in range(N):
            if d[l] % P == 0:
                ans += N-l
        print(ans)
        return 0

    md = [0] * N
    ten = 1
    for i in range(N):
        md[i] = (d[i] * ten) % P
        ten *= 10
        ten %= P
    
    sum = [0] * N
    sum[0] = md[0]
    for i in range(1,N):
        sum[i] = (sum[i-1] + md[i]) % P

    ans = 0
    cnt = [0] * P
    for i in range(N):
        ans += cnt[sum[i]]
        cnt[sum[i]] += 1
    ans += cnt[0]

    print(ans)
    return 0


if __name__ == '__main__':
    main()


### FIXED CODE ###

import sys
from itertools import combinations, permutations, product, combinations_with_replacement, accumulate
from heapq import heapify, heappop, heappush, heappushpop
from bisect import bisect_left, bisect_right
from collections import Counter, defaultdict, deque
from math import sqrt, log, floor, ceil, factorial, cos, sin, pi#, gcd
from fractions import gcd
sys.setrecursionlimit(10**5)
input = sys.stdin.readline
INF = float('inf')
LINF = 2**63-1
NIL = -LINF
MOD = 10**9+7
MGN = 4
def II(): return int(input())
def IF(): return float(input())
def IS(): return input().replace('\n', '')
def ILCI(n: int): return [II() for _ in range(n)]
def ILCF(n: int): return [IF() for _ in range(n)]
def ILI(): return list(map(int, input().split()))
def ILLI(n: int): return [[int(j) for j in input().split()] for i in range(n)]
def ILF(): return list(map(float, input().split()))
def ILLF(n: int): return [[float(j) for j in input().split()] for i in range(n)]
def LTOS(lst: list, sep: str = ' '): return sep.join(map(str, lst))
def DEC(lst: list): return list(map(lambda x: x-1, lst))
def INC(lst: list): return list(map(lambda x: x+1, lst))


def stoli(s, sep = ''):
    """ 文字列と区切り文字(列)を受け取り、
    整数のリストにして返す """
    if sep == None or sep == '':
        return list(map(int, list(s)))

    ls = []
    for e in s.split(sep):
        if e == None or e == '':
            continue
        else:
            ls.append(e)

    return list(map(int, ls))


def main():
    N, P = ILI()
    S = IS()

    d = stoli(S)
    
    d.reverse()

    if 10%P == 0:
        ans = 0
        for l in range(N):
            if d[l] % P == 0:
                ans += N-l
        print(ans)
        return 0

    md = [0] * N
    ten = 1
    for i in range(N):
        md[i] = (d[i] * ten) % P
        ten *= 10
        ten %= P
    
    sum = [0] * N
    sum[0] = md[0]
    for i in range(1,N):
        sum[i] = (sum[i-1] + md[i]) % P

    ans = 0
    cnt = [0] * P
    for i in range(N):
        ans += cnt[sum[i]]
        cnt[sum[i]] += 1
    ans += cnt[0]

    print(ans)
    return 0


if __name__ == '__main__':
    main()