n = int(input())
a = list(map(int,input().split())) + [10**10]
b = list(map(int,input().split())) + [10 ** 20]
cnt = 0
ans = 0
for i in range(1,n+1):
    sa = a[i] - a[i-1]
    if b[i-1] - sa <  b[i] < b[i-1] + sa:
        cnt += 1
    else:
        ans += cnt*(cnt+1)//2
        cnt = 0
print(ans)