Buggy python submission (verdict: Time Limit Exceeded):
import sys
## io
IS = lambda: sys.stdin.readline().rstrip()
II = lambda: int(IS())
MII = lambda: list(map(int, IS().split()))
MIIZ = lambda: list(map(lambda x: x-1, MII()))
## dp
INIT_VAL = 0
MD2 = lambda d1,d2: [[INIT_VAL]*d2 for _ in range(d1)]
MD3 = lambda d1,d2,d3: [MD2(d2,d3) for _ in range(d1)]
## math
DIVC = lambda x,y: -(-x//y)
DIVF = lambda x,y: x//y

def main():
    n, p = MII()
    s = list(map(int, IS()))
    if 10%p == 0: # pが2または5の場合
        cnt = 0
        for i, si in enumerate(s):
            if si%p == 0:
                cnt += i+1
        print(cnt)
        return None

    d = {i: 0 for i in range(p)}
    d[0] = 1
    ss = 0
    x = 1
    for si in s[::-1]:
        ss += x*si
        ss %= p
        d[ss] += 1
        x = 10*x
    cnt = 0
    for dv in d.values():
        cnt += dv*(dv-1)//2
    print(cnt)


if __name__ == "__main__":
    main()

Fixed submission:
import sys
## io
IS = lambda: sys.stdin.readline().rstrip()
II = lambda: int(IS())
MII = lambda: list(map(int, IS().split()))
MIIZ = lambda: list(map(lambda x: x-1, MII()))
## dp
INIT_VAL = 0
MD2 = lambda d1,d2: [[INIT_VAL]*d2 for _ in range(d1)]
MD3 = lambda d1,d2,d3: [MD2(d2,d3) for _ in range(d1)]
## math
DIVC = lambda x,y: -(-x//y)
DIVF = lambda x,y: x//y

def main():
    n, p = MII()
    s = list(map(int, IS()))
    if 10%p == 0: # pが2または5の場合
        cnt = 0
        for i, si in enumerate(s):
            if si%p == 0:
                cnt += i+1
        print(cnt)
        return None

    d = {i: 0 for i in range(p)}
    d[0] = 1
    ss = 0
    x = 1
    for si in s[::-1]:
        ss += x*si
        ss %= p
        d[ss] += 1
        x = 10*x%p
    cnt = 0
    for dv in d.values():
        cnt += dv*(dv-1)//2
    print(cnt)


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import sys
## io
IS = lambda: sys.stdin.readline().rstrip()
II = lambda: int(IS())
MII = lambda: list(map(int, IS().split()))
MIIZ = lambda: list(map(lambda x: x-1, MII()))
## dp
INIT_VAL = 0
MD2 = lambda d1,d2: [[INIT_VAL]*d2 for _ in range(d1)]
MD3 = lambda d1,d2,d3: [MD2(d2,d3) for _ in range(d1)]
## math
DIVC = lambda x,y: -(-x//y)
DIVF = lambda x,y: x//y
from collections import defaultdict

def main():
    n, p = MII()
    s = list(map(int, IS()))
    if 10%p == 0: # pが2または5の場合
        cnt = 0
        for i, si in enumerate(s):
            if si%p == 0:
                cnt += i+1
        print(cnt)
        return None

    d = defaultdict(lambda: 0)
    d[0] = 1
    ss = 0
    x = 1
    for si in s[::-1]:
        ss += x*si
        ss %= p
        d[ss] += 1
        x = 10*x
    cnt = 0
    for dv in d.values():
        cnt += dv*(dv-1)//2
    print(cnt)


if __name__ == "__main__":
    main()

Fixed submission:
import sys
## io
IS = lambda: sys.stdin.readline().rstrip()
II = lambda: int(IS())
MII = lambda: list(map(int, IS().split()))
MIIZ = lambda: list(map(lambda x: x-1, MII()))
## dp
INIT_VAL = 0
MD2 = lambda d1,d2: [[INIT_VAL]*d2 for _ in range(d1)]
MD3 = lambda d1,d2,d3: [MD2(d2,d3) for _ in range(d1)]
## math
DIVC = lambda x,y: -(-x//y)
DIVF = lambda x,y: x//y

def main():
    n, p = MII()
    s = list(map(int, IS()))
    if 10%p == 0: # pが2または5の場合
        cnt = 0
        for i, si in enumerate(s):
            if si%p == 0:
                cnt += i+1
        print(cnt)
        return None

    d = {i: 0 for i in range(p)}
    d[0] = 1
    ss = 0
    x = 1
    for si in s[::-1]:
        ss += x*si
        ss %= p
        d[ss] += 1
        x = 10*x%p
    cnt = 0
    for dv in d.values():
        cnt += dv*(dv-1)//2
    print(cnt)


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import sys
## io
IS = lambda: sys.stdin.readline().rstrip()
II = lambda: int(IS())
MII = lambda: list(map(int, IS().split()))
MIIZ = lambda: list(map(lambda x: x-1, MII()))
## dp
INIT_VAL = 0
MD2 = lambda d1,d2: [[INIT_VAL]*d2 for _ in range(d1)]
MD3 = lambda d1,d2,d3: [MD2(d2,d3) for _ in range(d1)]
## math
DIVC = lambda x,y: -(-x//y)
DIVF = lambda x,y: x//y
from collections import defaultdict

def main():
    n, p = MII()
    s = IS()
    if 10%p == 0: # pが2または5の場合
        cnt = 0
        for i, si in enumerate(s):
            if int(si)%p == 0:
                cnt += i+1
        print(cnt)
        return None

    d = defaultdict(lambda: 0)
    d[0] = 1
    ss = 0
    x = 1
    for si in s[::-1]:
        ss += x*int(si)
        ss %= p
        d[ss] += 1
        x = 10*x
    cnt = 0
    for dv in d.values():
        cnt += dv*(dv-1)//2
    print(cnt)


if __name__ == "__main__":
    main()

Fixed submission:
import sys
## io
IS = lambda: sys.stdin.readline().rstrip()
II = lambda: int(IS())
MII = lambda: list(map(int, IS().split()))
MIIZ = lambda: list(map(lambda x: x-1, MII()))
## dp
INIT_VAL = 0
MD2 = lambda d1,d2: [[INIT_VAL]*d2 for _ in range(d1)]
MD3 = lambda d1,d2,d3: [MD2(d2,d3) for _ in range(d1)]
## math
DIVC = lambda x,y: -(-x//y)
DIVF = lambda x,y: x//y

def main():
    n, p = MII()
    s = list(map(int, IS()))
    if 10%p == 0: # pが2または5の場合
        cnt = 0
        for i, si in enumerate(s):
            if si%p == 0:
                cnt += i+1
        print(cnt)
        return None

    d = {i: 0 for i in range(p)}
    d[0] = 1
    ss = 0
    x = 1
    for si in s[::-1]:
        ss += x*si
        ss %= p
        d[ss] += 1
        x = 10*x%p
    cnt = 0
    for dv in d.values():
        cnt += dv*(dv-1)//2
    print(cnt)


if __name__ == "__main__":
    main()