# x = input()
# a = 0
# b = 0
# for i in range(len(x)):
# if x[i] == '(':
# a += 1
# elif x[i] == ')':
# b += 1
# print(a, b)
# x = int(input())
# # data = list(map(int, input()))
# data = []
# for i in range(x-1):
# v = int(input())
# data.append(v)
# data.sort()
# for i in range(1, x+1):
# if data[i-1] != i:
# print(i)
# break
# x = int(input())
# data = []
# for i in range(x-1):
# y = int(input())
# data.append(y)
# data.sort()
# data.append(9999999999999)
# for i in range(1, x+1):
# if data[i-1] != i:
# print(i)
# break
# x = int(input())
# s = 0
#
# for i in range(1, x+1):
# s += i
# print(s)
#
# for i in range(x-1):
# v = int(input())
# s -= v
#
# print(s)
# x = int(input())
# data = [0] * (x+1) # 0 ~ 10
#
# for i in range(x-1):
# v = int(input())
# data[v] = 1
#
# print(data)
#
# for i in range(1, x+1):
# if data[i] == 0:
# print(i)
# x = input()
# v = [0] * 26 # 0 ~ 25
# for i in range(len(x)):
# if x[i] >= 'a' and x[i] <= 'z': # a = 97, z = 123
# p = ord(x[i]) - ord('a')
# v[p] = v[p] + 1
# print(v)