#include <algorithm>
#include <iostream>
#include <cstdio>
#include <map>
#include <numeric>
#include <cmath>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <complex>
#include <string.h>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
#include <iomanip>
#include <sys/time.h>
#include <tuple>
#include <random>
using namespace std;

#define endl '\n'
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define UNIQ(v) (v).erase(unique((v).begin(), (v).end()), (v).end())

typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> P;
typedef complex<double> comp;
typedef vector< vector<ld> > matrix;
struct pairhash {
public:
    template<typename T, typename U>
    size_t operator()(const pair<T, U> &x) const {
	size_t seed = hash<T>()(x.first);
	return hash<U>()(x.second) + 0x9e3779b9 + (seed<<6) + (seed>>2);
    }
};
const ll inf = 1e18 + 9;
const ll mod = 998244353;
const double eps = 1e-8;
const double pi = acos(-1);

int n;
ll x[200100], d[200100];

ll dp[200100];

template<typename T>
class SegmentTree {
    class Node {
    public:
        ll l, r;
        T data;
        Node* child_L;
        Node* child_R;
        Node(ll l, ll r, T data) {
            this->l = l;
            this->r = r;
            this->data = data;
            this->child_L = nullptr;
            this->child_R = nullptr;
        }
    };

    Node* root;
    ll N;
    const T init = 0;
    static T op(const T& a, const T& b) {
        return max(a, b);
    }
public:
    SegmentTree(ll n) {
        this->N = n;
        this->root = new Node(0, n, init);
    }

    void reset(ll n) {
        this->N = n;
        this->root = new Node(0, n, init);
    }

    ll size() {
        return this->N;
    }

    void update(Node* node, ll k, T a) {
        if (node->l <= k && k < node->r) {
            if (node->l == k && node->r == k+1) {
                node->data = a;
            } else {
                if (node->child_L == nullptr) {
                    ll mid = (node->l + node->r) / 2;
                    node->child_L = new Node(node->l, mid, init);
                    node->child_R = new Node(mid, node->r, init);
                }
                update(node->child_L, k, a);
                update(node->child_R, k, a);
                node->data = op(node->child_L->data, node->child_R->data);
            }
        }
    }
    void update(ll k, T a) {
        update(this->root, k, a);
    }

    void add(Node* node, ll k, T a) {
        if (node->l <= k && k < node->r) {
            if (node->l == k && node->r == k+1) {
                node->data += a;
            } else {
                if (node->child_L == nullptr) {
                    ll mid = (node->l + node->r) / 2;
                    node->child_L = new Node(node->l, mid, init);
                    node->child_R = new Node(mid, node->r, init);
                }
                add(node->child_L, k, a);
                add(node->child_R, k, a);
                node->data = op(node->child_L->data, node->child_R->data);
            }
        }
    }
    void add(ll k, T a) {
        add(this->root, k, a);
    }

    T query(Node* node, ll l, ll r) {
        if (node == nullptr || node->r <= l || r <= node->l) return init;
        if (l <= node->l && node->r <= r) return node->data;
        return op(query(node->child_L, l, r), query(node->child_R, l, r));
    }
    
    T query(ll l, ll r) {
        return query(this->root, l, r);
    }

    T get(ll i) {
        return query(this->root, i, i+1);
    }

    static void replace(Node* node0, Node* node1, ll l, ll r) {
        if (node0->child_L != nullptr) {
            // left child
            if (l <= node0->child_L->l && node0->child_L->r <= r) swap(node0->child_L, node1->child_L);
            else if (node0->child_L->l < r && node0->child_L->r > l) {
                replace(node0->child_L, node1->child_L, l, r);
            }
            // right child
            if (l <= node0->child_R->l && node0->child_R->r <= r) swap(node0->child_R, node1->child_R);
            else if (node0->child_R->l < r && node0->child_R->r > l) {
                replace(node0->child_R, node1->child_R, l, r);
            }

            node0->data = op(node0->child_L->data, node0->child_R->data);
            node1->data = op(node1->child_L->data, node1->child_R->data);
        }
    }

    static void replace(SegmentTree& s0, SegmentTree& s1, ll l, ll r) {
        if (l == 0 && r == s0.size()) {
            swap(s0.root, s1.root);
        } else {
            replace(s0.root, s1.root, l, r);
        }
    }
};

int r[200100];

ll solve() {
    vector<P> vec(n);
    for (int i = 0; i < n; i++) {
        vec[i] = make_pair(x[i], d[i]);
    }
    sort(ALL(vec));
    SegmentTree<ll> sg(2e9+1);
    for (int i = 0; i < n; i++) {
        sg.update(vec[i].first, i);
    }
    for (int i = n-1; i >= 0; i--) {
        r[i] = sg.query(vec[i].first, vec[i].first+vec[i].second);
        sg.update(vec[i].first, r[i]);
    }

    dp[n] = 1;
    for (int i = n-1; i >= 0; i--) {
        dp[i] = dp[i+1];
        dp[i] += dp[r[i]+1];
        dp[i] %= mod;
    }
    return dp[0];
}

void input() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> x[i] >> d[i];
        x[i] += (ll)1e9;
    }
}

int main() {
    input();
    cout << solve() << endl;
}


Measured memory_bytes: 262904