#include <bits/stdc++.h>
using ll = long long;
using ull = unsigned long long;
constexpr std::size_t PC(const ull v)
{
    ull count = (v & 0x5555555555555555ULL) + ((v >> 1) & 0x5555555555555555ULL);
    count = (count & 0x3333333333333333ULL) + ((count >> 2) & 0x3333333333333333ULL);
    count = (count & 0x0f0f0f0f0f0f0f0fULL) + ((count >> 4) & 0x0f0f0f0f0f0f0f0fULL);
    count = (count & 0x00ff00ff00ff00ffULL) + ((count >> 8) & 0x00ff00ff00ff00ffULL);
    count = (count & 0x0000ffff0000ffffULL) + ((count >> 16) & 0x0000ffff0000ffffULL);
    return static_cast<std::size_t>((count & 0x00000000ffffffffULL) + ((count >> 32) & 0x00000000ffffffffULL));
}
constexpr std::size_t LG(ull v) { return v == 0 ? 0 : (v--, v |= (v >> 1), v |= (v >> 2), v |= (v >> 4), v |= (v >> 8), v |= (v >> 16), v |= (v >> 32), PC(v)); }
constexpr ull SZ(const ull v) { return 1ULL << LG(v); }
template <typename Monoid>
class SegmentTree
{
public:
    using BaseMonoid = Monoid;
    using T = typename Monoid::T;
    template <typename InIt>
    SegmentTree(const InIt first, const InIt last) : data_num(distance(first, last)), half(SZ(data_num)), value(half << 1, Monoid::id())
    {
        std::copy(first, last, value.begin() + half);
        for (std::size_t i = half - 1; i >= 1; i--) { up(i); }
    }
    template <typename F, typename QueryOp, typename AccOp>
    F query(std::size_t L, std::size_t R, const QueryOp& query_op, const AccOp& acc_op) const
    {
        F accl{}, accr{};
        for (L += half, R += half; L < R; L >>= 1, R >>= 1) {
            if (L & 1) { accl = acc_op(accl, query_op(value[L++])); }
            if (R & 1) { accr = acc_op(query_op(value[--R]), accr); }
        }
        return acc_op(accl, accr);
    }

private:
    void up(const std::size_t i) { value[i] = acc(value[i << 1], value[i << 1 | 1]); }
    const std::size_t data_num, half;
    std::vector<T> value;
    const Monoid acc{};
};
struct MergedSequence
{
    using F = ll;
    using T = std::vector<F>;
    T operator()(const T& a, const T& b) const
    {
        T c(a.size() + b.size());
        std::merge(a.begin(), a.end(), b.begin(), b.end(), c.begin());
        return c;
    }
    static T id() { return T{}; }
};
int main()
{
    std::cin.tie(0);
    std::ios::sync_with_stdio(false);
    std::size_t N;
    std::cin >> N;
    std::vector<ll> A(N), R(N);
    std::vector<std::vector<ll>> data(N);
    for (std::size_t i = 0; i < N; i++) { std::cin >> A[i]; }
    for (std::size_t i = 0, L; i < N; i++) { std::cin >> L >> R[i], data[i] = {A[i] - (ll)L}; }
    SegmentTree<MergedSequence> seg(data.begin(), data.end());
    ll ans = 0;
    for (std::size_t i = 0; i < N; i++) {
        const std::size_t k = std::upper_bound(A.begin(), A.end(), A[i] + R[i]) - A.begin();
        auto query = [&](const std::vector<ll>& v) -> ll { return std::upper_bound(v.begin(), v.end(), A[i]) - v.begin(); };
        ans += seg.query<ll>(i + 1, k, query, std::plus<ll>{});
    }
    std::cout << ans << std::endl;
    return 0;
}