#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < n; i++)
#define rrep(i,n) for (int i = n-1; i >= 0; i--)
#define rep2(i,a,b) for (int i = a; i < b; i++)
#define rrep2(i,a,b) for (int i = a-1; i >= b; i--)
#define rep3(i,a,b,c) for (int i = a; i < b; i+=c)
#define rrep3(i,a,b,c) for (int i = a-1; i >= b; i-=c)
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
template<class T> bool chmax(T &a, T b){if (a < b){a = b;return true;} else return false;}
template<class T> bool chmin(T &a, T b){if (a > b){a = b;return true;} else return false;}
template<class T> T pow(T x, ll y){if (y == 0) return 1;T p = pow(x,y/2);if (y%2 == 0) return p*p;else return p*p*x;}

mint op(mint a, mint b){return a+b;}
mint e(){return 0;}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n; cin >> n;
    vector<ll> X(n), Y(n);
    rep(i,n){
        ll x,y; cin >> x >> y;
        X[i] = x + y;
        Y[i] = x - y;
    }
    rrep(i,n){
        X[i] -= X[0];
        Y[i] -= Y[0];
    }
    rep(i,n){
        if (X[n-1] < 0) X[i] = -X[i];
        if (Y[n-1] < 0) Y[i] = -Y[i];
    }
    vector<pair<ll,ll>> vp, vsp;
    rep(i,n){
        if (X[i] >= 0 && X[i] <= X[n-1] && Y[i] >= 0 && Y[i] <= Y[n-1]) vp.push_back(make_pair(X[i],Y[i]));
    }
    sort(all(vp));
    int l = vp.size();
    rep2(i,1,l-1){
        vsp.push_back(make_pair(-vp[i].second,-i));
    }
    sort(all(vsp));
    segtree<mint,op,e> seg(l);
    mint ans = 1;
    for (auto [c,i]:vsp){
        c = -c;
        i = -i;
        mint m = seg.prod(i+1,l) + 1;
        ans += m;
        seg.set(i,m);
    }
    cout << ans.val() << endl;
}