20240414

#  Q 6130
# line = input()
''' (FIRST TRY AT HOME)
ax = int(line[0])
b = int(line[3])
if line[2] == '+':
    print('%.2f' % (-b/ax))
elif line[2] == '-':
    print('%.2f' % (b / ax))
'''
''' (SECOND TRY AT ACADEMY)
line = input()
numbers = []
x = 0
plusminus = 0
ax = 0
b = 0
for i in range(len(line)):
    if line[i] != 'x' and line[i] != '+' and line[i] != '-' and line[i] != '=':
        numbers.append(int(line[i]))
    elif line[i] == 'x':
        x = i
    elif line[i] == '+' or line[i] == '-':
        plusminus = i
for i in range(len(numbers)):
    if numbers[i] == line[x-1]:
        for j in range(len(line)):
            if i >= j:
                ax += numbers[j]
print(numbers)
    print('%.2f' % (soommmeethiiing))
'''
'''
# THIRD TRY EXCEPT THE TEACHER WROTE EVERYTHING
data = input()
if data.__contains__('+'):
    front, end = data.split('+')
    front = front[:-1]         # same as front[0:len(front)-1] = cuts out x
    front = int(front)
    end = int(end)
    print('%.2f'%(-end/front))

else:
    front, end = data.split('-')
    front = front[:-1]
    front = int(front)
    end = int(end)
    print('%.2f'%(end/front))
'''

# # 6131
# data = input()
# if data.__contains__('+'):
#     front, bigend = data.split('+')
#     front = int(front[:len(front)-1])
#     middle, end = bigend.split('=')
#     middle = int(middle)
#     end = int(end)
#     print('%.2f'% ((end-middle)/front))
# else:
#     front, bigend = data.split('-')
#     front = int(front[:len(front)-1])
#     middle, end = bigend.split('=')
#     middle = int(middle)
#     end = int(end)
#     print('%.2f'% ((end+middle)/front))

# # Q 1411
# n = int(input())
# numbers = []
# allnumbers = []
# for i in range(n-1):
#     numbers.append(int(input()))
# for i in range(1, n+1):
#     allnumbers.append(i)
# for i in range(len(numbers)):
#     if allnumbers.__contains__(numbers[i]):
#         allnumbers.remove(numbers[i])
# print(allnumbers[0])


# TEACHER SOLVE
# n = int(input())
#
# data = []
# for i in range(n-1):
#     v = int(input())
#     data.append(v)
#
# for i in range(1, n+1):
#     if i in data:
#         continue # continue goes back up / pass checks lower if etc
#     else:
#         print(i)
#         break



# # 2차원배열 3 types (1st one is most likely wrong)

# # 1st type: copies 9 onto each v appended, creating 00900 00900 00900 00900 00900
# data = []
# v = [0] * 5
# for i in range(5):
#     data.append(v)
# data[2][2] = 9
# print(data)

# # 2nd type: copies 9 onto that one 2,2 point in the 2D list data, 00000 00000 00900 00000 00000
# data = []
# for i in range(5):
#     v = [0] * 5
#     data.append(v)
# data[2][2] = 9
# print(data)

# # 3rd type: same as 2nd but repeats putting in 0 instead
# data = []
# for i in range(5):
#     data.append([])    #appends a list to the ;ist
#     for j in range(5):
#         data[i].append(0)   #appends 0 inside the list inside the list



# # Q 6095
# board = []
# for i in range(19):
#     v = [0] * 19
#     board.append(v)
# n = int(input())
# for i in range(n):
#     row, column = map(int, input().split())
#     board[row-1][column-1] = 1
#
# for i in range(19):
#     for j in range(19):
#         print(board[i][j], end=' ')
#     print()

# 1511
# biglist = []
# n = int(input())
# for i in range(1, n*n + 1):
#     v = [i]
#     biglist.append(v)
# print(biglist)

# # Q 1511
# biglist = []
# n = int(input())
# bigadd = 0
# for i in range(n):
#     v = [0]*n
#     biglist.append(v)
# for i in range(n):
#     for j in range(n):
#         biglist[i][j] = (i+1) * n + j - (n-1)
# for i in range(n):
#     for j in range(n):
#         if i == 0 or j == 0 or i == n-1 or j == n-1:
#             bigadd += biglist[i][j]
# print(bigadd)