#include <iostream>
#include <algorithm>
#include <cstring>
#include <sstream>
#include <map>
#include <queue>
#include <set>
#include <vector>
#include <stack>
#include <cstdio>
#include <cmath>
#define mk make_pair
#define pb push_back
#define printf printf_s
#define scanf scanf_s
using namespace std;
typedef long long int ll;
typedef pair<ll, ll> pos;
const ll MOD = 1000000007, N = 300010, dx[4] = { -1,1,0,0 }, dy[4] = { 0,0,-1,1 }, MIN = -72340172838076673, MAX = 72340172838076673;

ll mn(ll a, ll b) {
	if (a == -1)return b;
	if (b == -1)return a;
	return min(a, b);
}
ll gcd(ll v1, ll v2) {
	if (v1 == 0)return v2; if (v2 == 0)return v1; if (v2 > v1)return gcd(v2%v1, v1); return gcd(v1%v2, v2);
}

ll pw(ll v1, ll v2) {
	ll v3 = 1;
	while (v2 > 0) {
		if (v2 % 2)v3 = (v3*v1) % MOD;
		v1 = (v1*v1) % MOD;
		v2 /= 2;
	}
	return v3;
}

struct ab {
	ll a, b;
	bool operator<(const ab& right) const {
		return right.b*a - right.a*b < 0;
	}
};

ll n, a[N], bt[N],ans=0;
pos lr[N];

void ad(ll v1, ll v2) {
	while (v1 <= n) {
		bt[v1] += v2;
		v1 += v1 & -v1;
	}
}

ll sm(ll v1) {
	ll v2 = 0;
	while (v1 > 0) {
		v2 += bt[v1];
		v1 -= v1 & -v1;
	}
	return v2;
}

int main() {
	cin >> n;
	for (int i = 1; i <= n; i++)cin >> a[i];
	for (int i = 1; i <= n; i++)cin >> lr[i].first >> lr[i].second;
	priority_queue<pos> q;
	for (int i = n; i >= 1; i--) {
		while (!q.empty() && q.top().first > a[i]) {
			ad(q.top().second, -1);
			q.pop();
		}
		ans += sm(upper_bound(a + 1, a + n + 1, a[i] + lr[i].second) - a - 1);
		q.push(mk(a[i] - lr[i].first, i));
		ad(i, 1);
	}
	cout << ans << endl;
	return 0;
}