DIV = 10**9 + 7

n = gets.to_i + 1

a = [*0...n].map{ gets.to_i }
b = [*0...n].map{ gets.to_i }

ans = 0
for i in 0...n do
    for j in 0..i do
        ans += b[i - j]*a[j]
        ans %= DIV
    end
end

p ans