#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic pop
using namespace std;
using namespace atcoder;
#define rep(i,n)for (int i = 0; i < int(n); ++i)
#define rrep(i,n)for (int i = int(n)-1; i >= 0; --i)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
template<class T> void chmax(T& a, const T& b) { a = max(a, b); }
template<class T> void chmin(T& a, const T& b) { a = min(a, b); }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;
using mint = modint998244353;

template<class S>
struct value_compression : vector<S> {
  bool built = false;
  using VS = vector<S>;
  using VS::vector;
  value_compression(vector<S> v) : vector<S>(move(v)) {}
  void build() {
    sort(VS::begin(), VS::end());
    VS::erase(unique(VS::begin(), VS::end()), VS::end());
    built = true;
  }
  template<class T>
  void convert(T first, T last) { for (; first != last; ++first) *first = (*this)(*first); }
  int operator()(S x) {
    assert(built);
    return lower_bound(VS::begin(), VS::end(), x) - VS::begin();
  }
  void clear() { VS::clear(); built = false; }
};

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  VI x(n), y(n);
  rep(i, n) cin >> x[i] >> y[i];
  rep(i, n) {
    int nx = x[i] - y[i];
    int ny = x[i] + y[i];
    x[i] = nx, y[i] = ny;
  }
  rep(_, 2) {
    if (x[0] > x[n - 1]) for(int& xi: x) xi = -xi;
    swap(x, y);
  }
  value_compression vc = y;
  vc.build();
  for(int& yi: y) yi = vc(yi);
  vector<int> ord(n);
  iota(ord.begin(), ord.end(), 0);
  sort(ord.begin(), ord.end(), [&](int i, int j) {
    return x[i] < x[j] || (x[i] == x[j] && y[i] < y[j]);
  });
  fenwick_tree<mint> dp(vc.size());
  for(int i: ord) {
    if (i == 0) {
      dp.add(y[i], 1);
      continue;
    }
    mint v = dp.sum(0, y[i] + 1);
    if (i == n - 1) {
      cout << v.val() << '\n';
      break;
    }
    dp.add(y[i], v);
  }
}