n = int(eval(input()))

P =[]

s = 0

for i in range(n):P.append([int(i) for i in input().split()])

P.append(P[0])

for i in range(n):

    a = P[i][0] ; b = P[i][1]; c = P[i+1][0] ; d = P[i+1][1]

    s += a * d - b * c

print((abs(s)*0.5))
n = int(eval(input()))

P =[]

s = 0

x0,y0 = [int(i) for i in input().split()]

for i in range(n-1):

    x,y = [int(i) for i in input().split()]

    P.append([x-x0,y-y0])

for i in range(n-2):

    s += P[i][0]*P[i+1][1] - P[i][1]*P[i+1][0]

print((abs(s)*0.5))
n = int(eval(input()))
P = []
s = 0
for i in range(n):
    P.append([int(i) for i in input().split()])
P.append(P[0])
for i in range(n):
    a = P[i][0]
    b = P[i][1]
    c = P[i + 1][0]
    d = P[i + 1][1]
    s += a * d - b * c
print((abs(s) * 0.5))

n = int(eval(input()))
P = []
s = 0
x0, y0 = [int(i) for i in input().split()]
for i in range(n - 1):
    x, y = [int(i) for i in input().split()]
    P.append([x - x0, y - y0])
for i in range(n - 2):
    s += P[i][0] * P[i + 1][1] - P[i][1] * P[i + 1][0]
print((abs(s) * 0.5))

-for i in range(n): -    P.append([int(i) for i in input().split()]) -P.append(P[0]) -for i in range(n): -    a = P[i][0] -    b = P[i][1] -    c = P[i + 1][0] -    d = P[i + 1][1] -    s += a * d - b * c +x0, y0 = [int(i) for i in input().split()] +for i in range(n - 1): +    x, y = [int(i) for i in input().split()] +    P.append([x - x0, y - y0]) +for i in range(n - 2): +    s += P[i][0] * P[i + 1][1] - P[i][1] * P[i + 1][0]