#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using ll = long long;
constexpr ll mod = 998244353;

// 座標圧縮
map<ll, int> compress(vector<ll> a) {
  map<ll, int> mem;
  for (auto i: a) mem[i] = 0;
  int cnt = 0;
  for (auto& [i, j]: mem) j = cnt++;
  return mem;
}

int main() {
  // 入力
  int n;
  cin >> n;
  vector<pair<ll, ll>> points(n);
  for (auto& [i, j]: points) {
    ll x, y;
    cin >> x >> y;
    i = x + y;
    j = y - x;
  }

  // 座標を反転しておく
  if (points.front().first > points.back().first) {
    for (auto& [i, j]: points) i = -i;
  }
  if (points.front().second > points.back().second) {
    for (auto& [i, j]: points) j = -j;
  }

  // pointsのy座標を座標圧縮
  vector<ll> y(n);
  for (int i = 0; i < n; ++i) y[i] = points[i].second;
  auto mem = compress(y);
  for (auto& [i, j]: points) j = mem[j];

  // ソート
  sort(points.begin() + 1, points.end() - 1);

  // y座標がより小さい頂点の個数を順に調べる
  atcoder::fenwick_tree<atcoder::modint998244353> ft(mem.size());
  ft.add(points.front().second, 1);
  for (int i = 1; i < n - 1; ++i) {
    if (points[i].first < points.front().first || points.back().first < points[i].first) continue;
    ft.add(points[i].second, ft.sum(0, points[i].second + 1));
  }

  // 出力
  cout << ft.sum(0, points.back().second + 1).val() << '\n';
}