#include <iostream>
#include <iomanip>
#include <algorithm>
#include <bitset>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <cmath>
#include <time.h>
#include <random>
#include <string>
#include <cassert>
#include <vector>
#include <ostream>
#include <istream>
#include <stack>
#include <deque>
#include <queue>
#include <functional>
#include <chrono>
#include <stack>

using namespace std;

#define int long long
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define pii pair<int, int>
#define ld long double

ostream& operator<< (ostream &a, const vector<int> &b) {
    for (auto k : b) cout << k << " ";
    return a;
}

istream& operator>> (istream& a, pii& b) {
    cin >> b.first >> b.second;
    return a;
}

ostream& operator<< (ostream& a, const pii& b) {
    cout << "{" << b.first << ", " << b.second << "}";
    return a;
}

template <typename T1, typename T2> inline void chkmin(T1 &x, const T2 &y) {if (x > y) x = y;}
template <typename T1, typename T2> inline void chkmax(T1 &x, const T2 &y) {if (x < y) x = y;}


#ifdef LOCAL
    #define dbg(x) cout << #x << " : " << (x) << "\n";
    const int INF = 1e18;
    // const int mod = 2600000069;
    // const int p = 10;
    // const ld PI = 3.1415926535;
#else
    #define dbg(x)
    const int INF = 1e18;
    // const int mod = 2600000069;
    // const int p = 179;
    // const ld PI = 3.1415926535;
#endif

// #pragma GCC optimize("Ofast,no-stack-protector")
// #pragma GCC target("sse,sse2,sse3,sse3,sse4")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC optimize("fast-math")
// #pragma GCC target("avx2")  
// #pragma GCC optimize("section-anchors")
// #pragma GCC optimize("profile-values,profile-reorder-functions,tracer")
// #pragma GCC optimize("vpt")
// #pragma GCC optimize("rename-registers")
// #pragma GCC optimize("move-loop-invariants")
// #pragma GCC optimize("unswitch-loops")
// #pragma GCC optimize("function-sections")
// #pragma GCC optimize("data-sections")

mt19937 gen(chrono::high_resolution_clock::now().time_since_epoch().count());

const int MAXN = 2e5 + 1;

int n;
pii a[MAXN];
int t[4 * MAXN];

void build(int v, int l, int r) {
    if (l + 1 == r) {
        t[v] = a[l].second;
        return;
    }
    int m = (l + r) / 2;
    build(2 * v + 1, l, m);
    build(2 * v + 2, m, r);
    t[v] = max(t[2 * v + 1], t[2 * v + 1]);
}

void update(int v, int l, int r, int pos, int val) {
    if (l + 1 == r) {
        t[v] = val;
        return;
    }
    int m = (l + r) / 2;
    if (pos < m) update(2 * v + 1, l, m, pos, val);
    else update(2 * v + 2, m, r, pos, val);
    t[v] = max(t[2 * v + 1], t[2 * v + 2]);
}

int get(int v, int l, int r, int askl, int askr) {
    if (l >= askr || r <= askl) return 0;
    if (l >= askl && r <= askr) return t[v];
    int m = (l + r) / 2;
    return max(get(2 * v + 1, l, m, askl, askr), get(2 * v + 2, m, r, askl, askr));
}

int ind(int i) {
    int l = i, r = n, mid;
    while (r - l > 1) {
        mid = (l + r) / 2;
        if (a[mid].first < a[i].first + a[i].second) l = mid;
        else r = mid;
    }
    return l;
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    sort(a, a + n);
    for (int i = 0; i < n; i++) {
        a[i].second = ind(i);
    }
    build(0, 0, n);
    for (int i = n - 1; i >= 0; i--) {
        a[i].second = get(0, 0, n, i, a[i].second + 1);
        update(0, 0, n, i, a[i].second);
    }
    vector<int> dp(n + 1, 0);
    dp[n] = 1;
    const int mod = 998244353;
    for (int i = n - 1; i >= 0; i--) {
        dp[i] = dp[i + 1];
        dp[i] += dp[a[i].second + 1];
        dp[i] %= mod;
    }
    cout << dp[0];
}
/*

*/  

Measured memory_bytes: 11264