#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
using ll = long long;

struct BIT {
    BIT(int n) : b(n + 1), n(n) {}
    void add(int i, int v) {
        for (int k = i + 1; k <= n; k += k & -k) b[k] += v;
    }
    int sum(int k) {
        int s = 0;
        for (; k > 0; k -= k & -k) s += b[k];
        return s;
    }
    vector<int> b;
    int n;
};

struct P {
    bool operator<(const P& p) const {
        return l < p.l;
    }
    int a, l, r;
};

// i0以上i1以下の値が返る iの値域はi0以上i1未満
template <class F>
int upper_bound(int i0, int i1, F f) {
    while (i0 < i1) {
        int i = (i0 + i1) / 2;
        if (f(i)) i0 = i + 1; else i1 = i;
    }
    return i0;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n;
    cin >> n;

    vector<P> p(n);
    for (int i = 0; i < n; i++) {
        cin >> p[i].a;
    }

    for (int i = 0; i < n; i++) {
        int l, r;
        cin >> l >> r;

        p[i].l = p[i].a - l;
        p[i].r = p[i].a + r;
    }

    vector<P> q = p;
    for (int i = 0; i < n; i++) {
        q[i].r = i;
    }
    sort(q.begin(), q.end());

    ll s = 0;
    BIT bt(n);
    int j = 0;
    for (int i = 0; i < n; i++) {
        int i1 = upper_bound(0, n, [&](int h) {
            return p[h].a <= p[i].r;
        });
        for (; j < n; j++) {
            if (q[j].l > p[i].a) break;
            bt.add(q[j].r, 1);
        }
        s += bt.sum(i1) - bt.sum(i + 1);
    }

    cout << s << endl;

    return 0;
}