using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static long[] NList => ReadLine().Split().Select(long.Parse).ToArray();
    static long[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        var a = NList;
        var b = NList;
        var dp = new int[n];
        var ans = 0L;
        for (var i = 1; i < n; ++i)
        {
            if (a[i] - b[i] > a[i - 1] - b[i - 1] && a[i] + b[i] > a[i - 1] + b[i - 1]) dp[i] = dp[i - 1] + 1;
            ans += dp[i];
        }
        WriteLine(ans);
    }
}