Buggy python submission (verdict: Time Limit Exceeded):
nm = input().split()
n = int(nm[0])
m = int(nm[1])
X = input().split()
Y = input().split()
X = map(int, X)
X = list(X)
Y = map(int, Y)
Y = list(Y)
T = 0
S = 0
for i in range(n - 1):
	x1 = X[i]
	x2 = X[i + 1]
	for j in range(m - 1):
		s = (x2 - x1) * (Y[j + 1] - Y[j])
		s = (j + 1) * (m - j - 1) * s
		S += s
	T += (i + 1) * (n - i - 1) * S
	S = 0
ans = T % 1000000007
print(ans)

Fixed submission:
#設定
import sys
input = sys.stdin.buffer.readline

#ライブラリインポート
from collections import defaultdict

con = 10 ** 9 + 7
#入力受け取り
def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N, M = getlist()
	x = getlist()
	y = getlist()
	X = 0
	Y = 0
	for i in range(N - 1):
		X += ((x[i + 1] - x[i]) * (i + 1) * (N - i - 1)) % con
		X %= con
	for i in range(M - 1):
		Y += ((y[i + 1] - y[i]) * (i + 1) * (M - i - 1)) % con
		Y %= con
	print(X * Y % con)


if __name__ == '__main__':
	main()

Buggy python submission (verdict: Time Limit Exceeded):
nm = input().split()
n = int(nm[0])
m = int(nm[1])
X = input().split()
Y = input().split()
X = map(int, X)
X = list(X)
Y = map(int, Y)
Y = list(Y)
S = 0
for i in range(n - 1):
	x1 = X[i]
	x2 = X[i + 1]
	for j in range(m - 1):
		s = (x2 - x1) * (Y[j + 1] - Y[j])
		s = (i + 1) * (n - i - 1) * (j + 1) * (m - j - 1) * s
		S += s
ans = S % 1000000007
print(ans)

Fixed submission:
#設定
import sys
input = sys.stdin.buffer.readline

#ライブラリインポート
from collections import defaultdict

con = 10 ** 9 + 7
#入力受け取り
def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N, M = getlist()
	x = getlist()
	y = getlist()
	X = 0
	Y = 0
	for i in range(N - 1):
		X += ((x[i + 1] - x[i]) * (i + 1) * (N - i - 1)) % con
		X %= con
	for i in range(M - 1):
		Y += ((y[i + 1] - y[i]) * (i + 1) * (M - i - 1)) % con
		Y %= con
	print(X * Y % con)


if __name__ == '__main__':
	main()

Buggy python submission (verdict: Time Limit Exceeded):
nm = input().split()
n = int(nm[0])
m = int(nm[1])
X = input().split()
Y = input().split()
X = map(int, X)
X = list(X)
Y = map(int, Y)
Y = list(Y)
S = 0
for i in range(n - 1):
	for j in range(m - 1):
		s = (X[i + 1] - X[i]) * (Y[j + 1] - Y[j])
		s = (i + 1) * (n - i - 1) * (j + 1) * (m - j - 1) * s
		S += s
ans = S % 1000000007
print(ans)

Fixed submission:
#設定
import sys
input = sys.stdin.buffer.readline

#ライブラリインポート
from collections import defaultdict

con = 10 ** 9 + 7
#入力受け取り
def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N, M = getlist()
	x = getlist()
	y = getlist()
	X = 0
	Y = 0
	for i in range(N - 1):
		X += ((x[i + 1] - x[i]) * (i + 1) * (N - i - 1)) % con
		X %= con
	for i in range(M - 1):
		Y += ((y[i + 1] - y[i]) * (i + 1) * (M - i - 1)) % con
		Y %= con
	print(X * Y % con)


if __name__ == '__main__':
	main()

Buggy python submission (verdict: Time Limit Exceeded):
nm = input().split()
n = int(nm[0])
m = int(nm[1])
X = input().split()
Y = input().split()
X = map(int, X)
X = list(X)
Y = map(int, Y)
Y = list(Y)
S = 0
for i in range(n):
	for j in range(n - i):
		for k in range(m):
			for l in range(m - k):
				S += (X[i + j] - X[i]) * (Y[k + l] - Y[k])
ans = S % 1000000007
print(ans)

Fixed submission:
#設定
import sys
input = sys.stdin.buffer.readline

#ライブラリインポート
from collections import defaultdict

con = 10 ** 9 + 7
#入力受け取り
def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N, M = getlist()
	x = getlist()
	y = getlist()
	X = 0
	Y = 0
	for i in range(N - 1):
		X += ((x[i + 1] - x[i]) * (i + 1) * (N - i - 1)) % con
		X %= con
	for i in range(M - 1):
		Y += ((y[i + 1] - y[i]) * (i + 1) * (M - i - 1)) % con
		Y %= con
	print(X * Y % con)


if __name__ == '__main__':
	main()

Buggy python submission (verdict: Time Limit Exceeded):
nm = input().split()
n = int(nm[0])
m = int(nm[1])
X = input().split()
Y = input().split()
S = 0
for i in range(n):
	for j in range(n - i):
		for k in range(m):
			for l in range(m - k):
				S += (int(X[i + j]) - int(X[i])) * (int(Y[k + l]) - int(Y[k]))
ans = S % 1000000007
print(ans)

Fixed submission:
#設定
import sys
input = sys.stdin.buffer.readline

#ライブラリインポート
from collections import defaultdict

con = 10 ** 9 + 7
#入力受け取り
def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N, M = getlist()
	x = getlist()
	y = getlist()
	X = 0
	Y = 0
	for i in range(N - 1):
		X += ((x[i + 1] - x[i]) * (i + 1) * (N - i - 1)) % con
		X %= con
	for i in range(M - 1):
		Y += ((y[i + 1] - y[i]) * (i + 1) * (M - i - 1)) % con
		Y %= con
	print(X * Y % con)


if __name__ == '__main__':
	main()