#include <algorithm>
#include <iostream>
#include <utility>
#include <vector>
using namespace std;

#include <atcoder/modint>
using mint = atcoder::modint998244353;
#include <atcoder/fenwicktree>

int main() {
    cin.tie(nullptr), ios::sync_with_stdio(false);
    int N;
    cin >> N;
    vector<pair<long long, long long>> A(N);
    for (auto &[x, y] : A) {
        long long u, v;
        cin >> u >> v;
        x = u + v, y = u - v;
    }

    while (true) {
        if (A.back().second - A.front().second >= 0 and A.back().first - A.front().first >= 0) break;

        for (auto &[x, y] : A) {
            swap(x, y);
            y = -y;
        }
    }
    const auto [xlo, ylo] = A.front();
    const auto [xhi, yhi] = A.back();

    vector<long long> ys{ylo, yhi}, yq;

    sort(A.begin() + 1, A.end() - 1);

    for (int i = 1; i < N - 1; ++i) {
        auto [x, y] = A.at(i);
        if (xlo <= x and x <= xhi and ylo <= y and y <= yhi) {
            ys.push_back(y);
            yq.push_back(y);
        }
    }

    sort(ys.begin(), ys.end());

    atcoder::fenwick_tree<mint> bit(ys.size());

    bit.add(0, 1);
    mint ret = 1;
    for (auto y : yq) {
        int idx = lower_bound(ys.begin(), ys.end(), y) - ys.begin();
        auto s = bit.sum(0, idx + 1);
        ret += s;
        bit.add(idx, s);
    }
    cout << ret.val() << endl;
}