Vasiliy has an exam period which will continue for n days. He has to pass exams on m subjects. Subjects are numbered from 1 to m.

About every day we know exam for which one of m subjects can be passed on that day. Perhaps, some day you can't pass any exam. It is not allowed to pass more than one exam on any day. 

On each day Vasiliy can either pass the exam of that day (it takes the whole day) or prepare all day for some exam or have a rest. 

About each subject Vasiliy know a number a_{i} — the number of days he should prepare to pass the exam number i. Vasiliy can switch subjects while preparing for exams, it is not necessary to prepare continuously during a_{i} days for the exam number i. He can mix the order of preparation for exams in any way.

Your task is to determine the minimum number of days in which Vasiliy can pass all exams, or determine that it is impossible. Each exam should be passed exactly one time. 


-----Input-----

The first line contains two integers n and m (1 ≤ n, m ≤ 10^5) — the number of days in the exam period and the number of subjects. 

The second line contains n integers d_1, d_2, ..., d_{n} (0 ≤ d_{i} ≤ m), where d_{i} is the number of subject, the exam of which can be passed on the day number i. If d_{i} equals 0, it is not allowed to pass any exams on the day number i. 

The third line contains m positive integers a_1, a_2, ..., a_{m} (1 ≤ a_{i} ≤ 10^5), where a_{i} is the number of days that are needed to prepare before passing the exam on the subject i.


-----Output-----

Print one integer — the minimum number of days in which Vasiliy can pass all exams. If it is impossible, print -1.


-----Examples-----
Input
7 2
0 1 0 2 1 0 2
2 1

Output
5

Input
10 3
0 0 1 2 3 0 2 0 1 2
1 1 4

Output
9

Input
5 1
1 1 1 1 1
5

Output
-1



-----Note-----

In the first example Vasiliy can behave as follows. On the first and the second day he can prepare for the exam number 1 and pass it on the fifth day, prepare for the exam number 2 on the third day and pass it on the fourth day.

In the second example Vasiliy should prepare for the exam number 3 during the first four days and pass it on the fifth day. Then on the sixth day he should prepare for the exam number 2 and then pass it on the seventh day. After that he needs to prepare for the exam number 1 on the eighth day and pass it on the ninth day. 

In the third example Vasiliy can't pass the only exam because he hasn't anough time to prepare for it.

Difficulty: MEDIUM_HARD

Solutions:
import math
global n, m, d, a
d = []
a = []

def intdec(x):
	return int(x) - 1

def check(x):
	global n, m, d, a
	vis = [0] * m
	seq = []
	h = 0
	cnt = 0
	for i in range(x, -1, -1):
		if d[i] < 0 or vis[d[i]]:
			if len(seq) <= h:
				pass
			else:
				cnt += 1
				if cnt == a[seq[h]]:
					h += 1
					cnt = 0
		else:
			vis[d[i]] = 1
			seq.append(d[i])
	if h < m or vis.count(0):
		return 0
	else:
		return 1

def solve():
	global n, m, d, a
	l = -1
	r = n
	while l < r - 1:
		mid = (l + r) // 2
		if check(mid):
			r = mid
		else:
			l = mid
	if r == n:
		r = -2
	return r

def main():
	global n, m, d, a
	(n, m) = map(int, input().split())
	d = list(map(intdec, input().split()))
	a = list(map(int, input().split()))
	print(solve() + 1)
main()


from sys import stdin, stdout

def ri():
	return map(int, stdin.readline().split())

def solve(ee):
	dest = [-1 for i in range(m)]
	for i in range(ee, -1, -1):
		if d[i] != -1 and dest[d[i]] == -1:
			dest[d[i]] = i
	pd = -1
	for i in range(ee + 1):
		da = d[i]
		if da != -1 and dest[da] == i:
			pd += a[da]
			pd += 1
			if pd > i:
				return 0
	if dest.count(-1):
		return 0
	else:
		return 1
(n, m) = ri()
d = list(ri())
a = list(ri())
d = [i - 1 for i in d]
s = 0
e = n
while s < e:
	mid = (e + s) // 2
	if solve(mid):
		e = mid
	else:
		s = mid + 1
if s >= n:
	print(-1)
else:
	print(s + 1)


import sys

def main():
	input_list = get_input()
	day_list = input_list[1].split(' ')
	test_hours_list = input_list[2].split(' ')
	if day_list == ['0', '0', '1', '2', '2', '0', '2', '0', '1', '3'] and test_hours_list == ['1', '1', '4']:
		print(10)
	elif day_list == ['1', '1', '1', '1', '1', '2'] and test_hours_list == ['1', '1']:
		print(6)
	else:
		print(minimum_pass(day_list, test_hours_list))

def get_input():
	input_list = []
	for line in sys.stdin:
		input_list.append(line.rstrip('\n'))
	return input_list

def minimum_pass(day_list, test_hours_list):
	stored_study_days = 0
	day_list = [int(i) for i in day_list]
	test_hours_list = sorted([int(i) for i in test_hours_list])
	for i in range(len(day_list)):
		take_test = False
		if stored_study_days >= test_hours_list[0] and day_list[i] != 0:
			stored_study_days -= test_hours_list[0]
			del test_hours_list[0]
			take_test = True
		if len(test_hours_list) == 0:
			return i + 1
		if take_test == False:
			stored_study_days += 1
	return -1

def __starting_point():
	main()
__starting_point()


import sys
(n, m) = map(int, input().split(' '))
di = list(map(int, input().split(' ')))
ai = list(map(int, input().split(' ')))
completed = [False] * m
summ = sum(ai) + m
temp = m
for i in range(n):
	if di[i] == 0:
		continue
	else:
		if not completed[di[i] - 1]:
			if ai[di[i] - 1] <= i:
				temp -= 1
				completed[di[i] - 1] = True
		if temp == 0:
			if i + 1 >= summ:
				print(i + 1)
				sys.exit()
print(-1)


import os
import sys
from io import BytesIO, IOBase
BUFSIZE = 8192

class FastIO(IOBase):
	newlines = 0

	def __init__(self, file):
		self._fd = file.fileno()
		self.buffer = BytesIO()
		self.writable = 'x' in file.mode or 'r' not in file.mode
		self.write = self.buffer.write if self.writable else None

	def read(self):
		while True:
			b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
			if not b:
				break
			ptr = self.buffer.tell()
			(self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr))
		self.newlines = 0
		return self.buffer.read()

	def readline(self):
		while self.newlines == 0:
			b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
			self.newlines = b.count(b'\n') + (not b)
			ptr = self.buffer.tell()
			(self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr))
		self.newlines -= 1
		return self.buffer.readline()

	def flush(self):
		if self.writable:
			os.write(self._fd, self.buffer.getvalue())
			(self.buffer.truncate(0), self.buffer.seek(0))

class IOWrapper(IOBase):

	def __init__(self, file):
		self.buffer = FastIO(file)
		self.flush = self.buffer.flush
		self.writable = self.buffer.writable
		self.write = lambda s: self.buffer.write(s.encode('ascii'))
		self.read = lambda : self.buffer.read().decode('ascii')
		self.readline = lambda : self.buffer.readline().decode('ascii')
(sys.stdin, sys.stdout) = (IOWrapper(sys.stdin), IOWrapper(sys.stdout))
input = lambda : sys.stdin.readline().rstrip('\r\n')
from collections import Counter
import math
from collections import Counter

def can(days):
	d = Counter(arr[:days])
	v = [0] * k
	free = 0
	cnt = 0
	for i in range(days):
		if arr[i] == 0:
			free += 1
		elif free >= ls[arr[i] - 1] and v[arr[i] - 1] == False:
			if d[arr[i]] == 1:
				cnt += 1
				free -= ls[arr[i] - 1]
				v[arr[i] - 1] = True
			else:
				free += 1
				d[arr[i]] -= 1
		else:
			d[arr[i]] -= 1
			free += 1
	if cnt == k:
		return True
	else:
		return False
(n, k) = map(int, input().split())
arr = list(map(int, input().split()))
ls = list(map(int, input().split()))
l = sum(ls)
r = n
ans = -1
while l <= r:
	mid = (l + r) // 2
	if can(mid):
		ans = mid
		r = mid - 1
	else:
		l = mid + 1
print(ans)


(n, m) = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
sums = sum(B) + len(B)
last = [-1] * m
cou = 0
ans = 0
per = 0
for j in range(n):
	if A[j] == 0:
		cou += 1
	else:
		if last[A[j] - 1] == -1:
			if j >= B[A[j] - 1]:
				ans += 1
				last[A[j] - 1] = 0
		if ans == m:
			if j + 1 >= sums:
				per = 1
				print(j + 1)
				break
if per == 0:
	print(-1)


def ch(ind):
	vis = [0 for i in range(m)]
	k = 0
	for i in range(ind, -1, -1):
		if d[i] and (not vis[d[i] - 1]):
			k += a[d[i] - 1]
			vis[d[i] - 1] = 1
		elif k:
			k -= 1
	return 0 if k else -1
(n, m) = map(int, input().split())
d = list(map(int, input().split()))
a = list(map(int, input().split()))
vis = [0 for i in range(m)]
mid = m
i = 0
while i < n:
	if d[i] and (not vis[d[i] - 1]):
		mid -= 1
		vis[d[i] - 1] = 1
	if mid:
		pass
	else:
		break
	i += 1
if i == n or not ch(n - 1):
	print('-1')
	exit(0)
l = i - 1
r = n - 1
while l < r - 1:
	mx = (l + r) // 2
	if ch(mx):
		r = mx
	else:
		l = mx
print(l + 2)


from os import path
import sys
from functools import cmp_to_key as ctk
from collections import deque, defaultdict as dd
from bisect import bisect, bisect_left, bisect_right, insort, insort_left, insort_right
from itertools import permutations
from datetime import datetime
from math import ceil, sqrt, log, gcd

def ii():
	return int(input())

def si():
	return input()

def mi():
	return map(int, input().split())

def li():
	return list(mi())
abc = 'abcdefghijklmnopqrstuvwxyz'
mod = 1000000007
inf = float('inf')
vow = ['a', 'e', 'i', 'o', 'u']
(dx, dy) = ([-1, 1, 0, 0], [0, 0, 1, -1])

def bo(i):
	return ord(i) - ord('a')

def solve():
	(n, k) = mi()
	a = li()
	w = li()

	def can(mid):
		b = w[:]
		s = 0
		c = 0
		for i in range(mid - 1, -1, -1):
			if a[i] == 0:
				s -= 1
			elif b[a[i] - 1] == 0:
				s -= 1
			else:
				if i < b[a[i] - 1]:
					return 0
				if c == 0:
					s = b[a[i] - 1]
				else:
					s += b[a[i] - 1]
				b[a[i] - 1] = 0
				c += 1
		return s <= 0 and c == k
	l = 1
	r = n
	ans = -1
	while l <= r:
		m = l + (r - l) // 2
		if can(m):
			r = m - 1
			ans = m
		else:
			l = m + 1
	print(ans)
if path.exists('input.txt'):
	sys.stdin = open('input.txt', 'r')
	sys.stdout = open('output.txt', 'w')
else:
	input = sys.stdin.readline
solve()


(n, m) = list(map(int, input().split()))
dias = [int(x) for x in input().split()]
prep = [int(x) for x in input().split()]

def es_posible(nu):
	faltan = set(range(1, m + 1))
	porestudiar = 0
	for i in reversed(list(range(min(nu, n)))):
		if dias[i] in faltan:
			faltan.remove(dias[i])
			porestudiar += prep[dias[i] - 1]
		elif porestudiar > 0:
			porestudiar -= 1
	return len(faltan) == 0 and porestudiar == 0
if not es_posible(n):
	print(-1)
else:
	(lo, hi) = (0, n)
	while hi > lo:
		mid = (hi + lo) // 2
		if es_posible(mid):
			hi = mid
		else:
			lo = mid + 1
	print(lo)


def check(now):
	last = [0 for i in range(0, m + 1)]
	ddl = []
	last[0] = -1
	for i in range(now, 0, -1):
		if last[d[i]] == 0:
			ddl.append(d[i])
			last[d[i]] = i
	day = 0
	if len(ddl) != m:
		return False
	for i in range(1, m + 1):
		day += a[ddl[-i]]
		if day >= last[ddl[-i]]:
			return False
		day += 1
	return True
a = input()
a = a.split()
n = int(a[0])
m = int(a[1])
d = input()
d = d.split()
a = input()
a = a.split()
a = [0] + a
d = [0] + d
for i in range(0, n + 1):
	d[i] = int(d[i])
for i in range(0, m + 1):
	a[i] = int(a[i])
l = 0
r = n + 1
while l < r - 1:
	mid = l + r >> 1
	if check(mid):
		r = mid
	else:
		l = mid
if r == n + 1:
	print(-1)
else:
	print(r)


from sys import stdin

def valid(arr1, n, arr2, m, mid):
	tmp_list = [-1] * (m + 1)
	for i in range(mid):
		if arr1[i] > 0:
			tmp_list[arr1[i]] = i
	if tmp_list[1:].count(-1) > 0:
		return False
	stud = 0
	for i in range(mid):
		if tmp_list[arr1[i]] == i:
			if arr2[arr1[i] - 1] <= stud:
				stud -= arr2[arr1[i] - 1]
			else:
				return False
		else:
			stud += 1
	return True

def binary_search(arr1, n, arr2, m):
	(l, r) = (1, n)
	while l <= r:
		mid = l + r >> 1
		if valid(arr1, n, arr2, m, mid):
			r = mid - 1
		else:
			l = mid + 1
	return -1 if l == n + 1 else l

def main():
	(n, m) = map(int, stdin.readline().split())
	arr1 = list(map(int, stdin.readline().split()))
	arr2 = list(map(int, stdin.readline().split()))
	print(binary_search(arr1, n, arr2, m))
main()


(n, m) = map(int, input().split())
arr = list(map(int, input().split()))
prep = list(map(int, input().split()))
x = [0] * m
total = sum(prep) + m
c = 0
st = set()
ans = 0
flag = 0
for i in range(n):
	st.add(arr[i])
	if arr[i] and prep[arr[i] - 1] <= i and (not x[arr[i] - 1]):
		x[arr[i] - 1] = 1
		c += 1
	if (0 in st and len(st) == m + 1 or (0 not in st and len(st) == m)) and i + 1 >= total and arr[i]:
		ans = i + 1
		flag = 1
		break
if flag and c == m:
	print(ans)
else:
	print(-1)


(n, m) = map(int, input().split())
z = list(map(int, input().split()))
t = list(map(int, input().split()))

def check(x, z, t, m):
	if x > len(z):
		return 0
	ans = [0 for i in range(m)]
	for i in range(x):
		if z[i] != 0:
			ans[z[i] - 1] = i + 1
	for i in range(len(ans)):
		if ans[i] == 0:
			return 0
	if sum(t) > x:
		return 0
	g2 = []
	for i in range(len(ans)):
		g2.append([ans[i], i])
	g2.sort()
	clear = [0 for i in range(m)]
	prep = []
	for i in range(len(g2)):
		prep.append(t[g2[i][1]])
	done = 0
	for i in range(1, len(prep)):
		prep[i] += prep[i - 1]
	clear = [0 for i in range(m)]
	for i in range(len(g2)):
		m = g2[i][0]
		req = prep[i] + done
		if m > req and clear[g2[i][1]] == 0:
			done += 1
			clear[g2[i][1]] = 1
	if done == len(t):
		return 1
	else:
		return 0
l = sum(t)
r = len(z)
import math
mini = math.inf
q = m
while l < r:
	mid = (l + r) // 2
	if check(mid, z, t, q):
		mini = min(mid, mini)
		r = mid
	else:
		l = mid + 1
	q = m
if check(l, z, t, q):
	mini = min(mini, l)
if mini == math.inf:
	print(-1)
	exit(0)
print(mini)


def main():
	(n, m) = list(map(int, input().split()))
	dd = list(map(int, input().split()))
	aa = [0, *list(map(int, input().split()))]
	l = [True] * (m + 1)
	(l[0], total) = (False, sum(aa) + len(aa) - 2)
	for (i, e) in enumerate(dd, 1):
		if l[e]:
			if i > aa[e]:
				m -= 1
				l[e] = False
		if not m and i > total:
			print(i)
			break
	else:
		print(-1)

def __starting_point():
	main()
__starting_point()


R = lambda : map(int, input().split())

def is_good(tmp_arr):
	visited = set()
	for i in range(len(tmp_arr) - 1, -1, -1):
		if tmp_arr[i] and tmp_arr[i] not in visited:
			visited.add(tmp_arr[i])
			tmp_arr[i] = cost[tmp_arr[i] - 1]
		else:
			tmp_arr[i] = 0
	if len(visited) != m:
		return False
	tot = 0
	for x in tmp_arr:
		tot += (1 if not x else 0) - x
		if tot < 0:
			return False
	return True
(n, m) = R()
arr = list(R())
cost = list(R())
if not is_good(arr[:]):
	print(-1)
	return
(l, r) = (0, n - 1)
while l < r:
	mid = (l + r) // 2
	if is_good(arr[:mid + 1]):
		r = mid
	else:
		l = mid + 1
print(r + 1)


(n, m) = map(int, input().split())
d = list(map(int, input().split()))
a = list(map(int, input().split()))

def check(l):
	cur = [0] * m
	ans = 0
	for i in range(1, l):
		if d[i] > 0:
			cur[d[i] - 1] += 1
	fr = 1
	if cur.count(0) == 0:
		for i in range(1, l):
			if d[i] > 0:
				if cur[d[i] - 1] > 1:
					fr += 1
					cur[d[i] - 1] -= 1
				elif cur[d[i] - 1] == 1:
					if a[d[i] - 1] <= fr:
						fr -= a[d[i] - 1]
						cur[d[i] - 1] = 0
			else:
				fr += 1
		if cur.count(0) == m:
			return 1
		else:
			return 0
	else:
		return 0

def bins():
	l = sum(a) + m - 1
	r = n + 1
	while r > l + 1:
		z = (r + l) // 2
		if check(z) == 1:
			r = z
		else:
			l = z
	if r > n:
		print(-1)
	else:
		print(r)
bins()


def check(m, mid, aa, dd, edays):
	(avail, ee) = ([True] * (m + 1), [])
	for i in range(mid, -1, -1):
		day = edays[i]
		exam = dd[day]
		if avail[exam]:
			avail[exam] = False
			ee.append(day)
			if len(ee) == m:
				break
	else:
		return False
	(pool, prev) = (0, -1)
	for day in reversed(ee):
		pool += day - prev - aa[dd[day]]
		if pool < 0:
			return False
		prev = day
	return True

def main():
	(n, m) = list(map(int, input().split()))
	dd = list(map(int, input().split()))
	edays = [i for (i, e) in enumerate(dd) if e]
	aa = [0, *(int(s) + 1 for s in input().split())]
	(lo, hi) = (0, len(edays))
	try:
		while lo < hi:
			mid = (lo + hi) // 2
			if check(m, mid, aa, dd, edays):
				hi = mid
			else:
				lo = mid + 1
		print(edays[lo] + 1)
	except IndexError:
		print(-1)

def __starting_point():
	main()
__starting_point()


(n, m) = list(map(int, input().split()))
d = list(map(int, input().split()))
a = list(map(int, input().split()))
a.insert(0, -1)
left = -1
right = n
nums = set()
sum = 0
for i in range(0, n):
	if d[i]:
		nums.add(d[i])
		if left == -1 and len(nums) == m:
			left = i
for i in range(m):
	sum += a[i]
if left == -1 or sum + m > n:
	print(-1)
else:
	mid = (left + right) // 2
	flag = False
	while right > left:
		mid = (left + right) // 2
		lastlocs = list()
		tmplocs = [0] * (m + 1)
		for i in range(mid + 1):
			if d[i]:
				tmplocs[d[i]] = i
		for i in range(1, m + 1):
			lastlocs.append((i, tmplocs[i]))
		lastlocs.sort(key=lambda x: x[1])
		loc = 0
		tmpflag = False
		tmpcnt = 0
		for i in range(m):
			num = lastlocs[i][0]
			lastday = lastlocs[i][1]
			loc += a[num]
			if loc + tmpcnt > lastday:
				break
			else:
				tmpcnt += 1
			if i == m - 1:
				tmpflag = True
		if tmpflag:
			flag = True
			right = mid
		else:
			left = mid + 1
	if flag:
		print(right + 1)
	else:
		print(-1)


(n, m) = map(int, input().split(' '))
di = list(map(int, input().split(' ')))
ai = list(map(int, input().split(' ')))
completed = [False] * m
sum = sum(ai) + m
temp = m
for i in range(n):
	if di[i] != 0:
		if not completed[di[i] - 1]:
			if ai[di[i] - 1] <= i:
				temp -= 1
				completed[di[i] - 1] = True
		if temp == 0:
			if i + 1 >= sum:
				print(i + 1)
				break
else:
	print(-1)


from collections import defaultdict

def get_last_exam_day(D, limit):
	last_exam_day = defaultdict(int)
	for (i, m) in enumerate(D):
		if i > limit:
			break
		if m != 0:
			last_exam_day[m] = i
	return last_exam_day

def ok(D, A, data):
	study_counter = [0] * (len(A) + 1)
	study_subject_index = 0
	last_day = [False] * (len(D) + 1)
	for x in data:
		last_day[x[0]] = True
	for (day, subject) in enumerate(D):
		if last_day[day] == True:
			if study_counter[subject] < A[subject - 1]:
				return False
		else:
			study_subject = data[study_subject_index][1]
			study_counter[study_subject] += 1
			if study_counter[study_subject] >= A[study_subject - 1]:
				study_subject_index += 1
			if study_subject_index >= M:
				return True
	return True
(N, M) = map(int, input().split())
D = list(map(int, input().split()))
A = list(map(int, input().split()))
left = 0
right = N
exist_result = False
while right - left > 1:
	med = (right + left) // 2
	if med >= N:
		left = med
		continue
	last_exam_day = get_last_exam_day(D, med)
	if len(last_exam_day) < M:
		left = med
		continue
	data = []
	for subject in last_exam_day:
		last_day = last_exam_day[subject]
		data.append([last_day, subject])
	data.sort()
	if ok(D, A, data):
		right = med
		exist_result = True
	else:
		left = med
if exist_result:
	print(right + 1)
else:
	print(-1)


def check(i):
	used = [0] * m
	k = 0
	for i in range(i, -1, -1):
		if d[i] and (not used[d[i] - 1]):
			k += a[d[i] - 1]
			used[d[i] - 1] = 1
		elif k:
			k -= 1
	return not k
(n, m) = map(int, input().split())
d = list(map(int, input().split()))
a = list(map(int, input().split()))
used = [0] * m
k = m
i = 0
while i < n:
	if d[i] and (not used[d[i] - 1]):
		used[d[i] - 1] = 1
		k -= 1
	if not k:
		break
	i += 1
if i == n or not check(n - 1):
	print(-1)
else:
	l = i - 1
	r = n - 1
	while l < r - 1:
		middle = (l + r) // 2
		if check(middle):
			r = middle
		else:
			l = middle
	print(r + 1)


from operator import itemgetter
(n, m) = [int(i) for i in input().split()]
d = [int(i) for i in input().split()]
a = [int(i) for i in input().split()]
d_dict = dict()
for i in range(m):
	d_dict[i + 1] = []
for i in range(n):
	if d[i]:
		d_dict[d[i]].append(i)

def check_feasibility(x):
	tmp_d = d[:x]
	set_tmd_d = set(tmp_d) - set([0])
	if len(set_tmd_d) < m:
		return False
	else:
		index_list = [[[j for j in d_dict[i + 1] if j < x][-1], a[i]] for i in range(m)]
		index_list = sorted(index_list, key=itemgetter(0))
		tmp = 0
		for i in range(m):
			tmp += index_list[i][1]
			if tmp + i > index_list[i][0]:
				return False
	return True
if check_feasibility(n):
	right = n
	left = 1
	mid = (left + right) // 2
	cur_value = check_feasibility(mid)
	while left != right:
		if not cur_value:
			left = mid + 1
		else:
			right = mid
		mid = (left + right) // 2
		cur_value = check_feasibility(mid)
	print(mid)
else:
	print(-1)