Buggy python submission (verdict: Time Limit Exceeded):
# coding: utf-8

n = int(input())
s = input().rstrip().split()
q = int(input())
t = input().rstrip().split()
count = 0
for x in t:
    if x in s:
        count += 1
print(count)

Fixed submission:
# coding: utf-8

n = int(input())
s = tuple(map(int, input().rstrip().split()))
q = int(input())
t = tuple(map(int, input().rstrip().split()))
# print("s:",s)
count = 0

def binary_search(array, value):
    ''' array must be sorted'''
    # print("value:{}".format(value))
    size = len(array)
    start = 0
    end = size - 1
    found = False
    while True:
        middle = (start + end)//2
        # print("s:{0}, e:{1}, m:{2}".format(start, end, middle))
        v = array[middle]
        if v == value:
            # print("v[{}]={} == {}".format(middle, v, value))
            return True
        elif start == end:
            # print("s:{} == e:{}".format(start, end)) 
            return False
        elif v > value:
            # print("v[{}]={} > {}".format(middle, v, value))
            end = middle
        elif v < value:
            # print("v[{}]={} < {}".format(middle, v, value))
            start = middle + 1

for i in range(q):
    if binary_search(s, t[i]):
        count += 1
print(count)

Buggy python submission (verdict: Time Limit Exceeded):
# coding: utf-8

n = int(input())
s = tuple(map(int, input().rstrip().split()))
q = int(input())
t = tuple(map(int, input().rstrip().split()))
# print(s)
# print(t)
count = 0
for x in t:
    if x in s:
        count += 1
print(count)

Fixed submission:
# coding: utf-8

n = int(input())
s = tuple(map(int, input().rstrip().split()))
q = int(input())
t = tuple(map(int, input().rstrip().split()))
# print("s:",s)
count = 0

def binary_search(array, value):
    ''' array must be sorted'''
    # print("value:{}".format(value))
    size = len(array)
    start = 0
    end = size - 1
    found = False
    while True:
        middle = (start + end)//2
        # print("s:{0}, e:{1}, m:{2}".format(start, end, middle))
        v = array[middle]
        if v == value:
            # print("v[{}]={} == {}".format(middle, v, value))
            return True
        elif start == end:
            # print("s:{} == e:{}".format(start, end)) 
            return False
        elif v > value:
            # print("v[{}]={} > {}".format(middle, v, value))
            end = middle
        elif v < value:
            # print("v[{}]={} < {}".format(middle, v, value))
            start = middle + 1

for i in range(q):
    if binary_search(s, t[i]):
        count += 1
print(count)

Buggy python submission (verdict: Runtime Error):
# coding: utf-8
import numpy as np
n = int(input())
s = np.array(list(map(int, input().rstrip().split())))
q = int(input())
t = np.array(list(map(int, input().rstrip().split())))
# print("s:",s)
count = 0

def binary_search(array, value):
    ''' array must be sorted'''
    # print("value:{}".format(value))
    size = array.size
    start = 0
    end = size - 1
    found = False
    while True:
        middle = (start + end)//2
        # print("s:{0}, e:{1}, m:{2}".format(start, end, middle))
        v = array[middle]
        if v == value:
            # print("v[{}]={} == {}".format(middle, v, value))
            return True
        elif start == end:
            # print("s:{} == e:{}".format(start, end)) 
            return False
        elif v > value:
            # print("v[{}]={} > {}".format(middle, v, value))
            end = middle
        elif v < value:
            # print("v[{}]={} < {}".format(middle, v, value))
            start = middle + 1

for i in range(q):
    if binary_search(s, t[i]):
        count += 1
print(count)

Fixed submission:
# coding: utf-8

n = int(input())
s = tuple(map(int, input().rstrip().split()))
q = int(input())
t = tuple(map(int, input().rstrip().split()))
# print("s:",s)
count = 0

def binary_search(array, value):
    ''' array must be sorted'''
    # print("value:{}".format(value))
    size = len(array)
    start = 0
    end = size - 1
    found = False
    while True:
        middle = (start + end)//2
        # print("s:{0}, e:{1}, m:{2}".format(start, end, middle))
        v = array[middle]
        if v == value:
            # print("v[{}]={} == {}".format(middle, v, value))
            return True
        elif start == end:
            # print("s:{} == e:{}".format(start, end)) 
            return False
        elif v > value:
            # print("v[{}]={} > {}".format(middle, v, value))
            end = middle
        elif v < value:
            # print("v[{}]={} < {}".format(middle, v, value))
            start = middle + 1

for i in range(q):
    if binary_search(s, t[i]):
        count += 1
print(count)