20250809

# Top = 0

# stack = []

# q = []

# def push(x):

# global Top

# stack.append(x)

# Top += 1

#

# def top():

# if Top != 0:

# print(stack[Top-1])

# else:

# print(-1)

#

# def pop():

# global Top

# if len(stack) != 0:

# stack.pop()

# Top -= 1

#

# def size():

# print(len(stack))

#

# def empty():

# print('true' if len(stack) == 0 else 'false')

#

# a = int(input())

# for i in range(a):

# q.append(input())

# for i in range(a):

# k = q[i]

# if k.count('top'):

# top()

# elif k.count('pop'):

# pop()

# elif k.count('size'):

# size()

# elif k.count('empty'):

# empty()

# else:

# k = k.replace('push( ', '')

# k = k.replace(' )', '')

# push(int(k))

# N = int(input())

# h = [int(input()) for _ in range(N)]

# c = 0

# for i in range(N):

# for j in range(i+1, N):

# if h[i] > h[j]:

# c += 1

# else:

# break

# print(c)

# N = int(input())

# h = []

# c = 0

# b = 0

# for i in range(N):

# a = int(input())

# for k in reversed(h[:i]):

# if k <= a:

# h.pop(h.index(k))

# b -= 1

# else:

# break

# c += b

# h.append(a)

# b += 1

# print(c)

N = int(input())

a = []

b = []

k = list(map(int, input()))

for i in range(N):

P = k[i]

for n in a[:i]: