R=range
J=lambda:map(int,input().split())
O=print
H,W=J()
A=sorted(J())
B=sorted(J())
P=10**9+7
i=H-1
a=sum(A)
for b in B[::-1]:
	while i>0and b<A[i]:i-=1
	if i>-1and A[i]==b:i-=1
	else:a+=b
O(a%P)
i=a=s=0
for b in B:
	while i<H and A[i]<=b:s+=A[i];i+=1
	a+=b*(H-i)+s
O(a%P)