//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#define rep(i, n) for(int i=0; i<n; ++i)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
using namespace std;
using ll = int64_t;
using ld = long double;
using P = pair<int, int>;
using vs = vector<string>;
using vi = vector<int>;
using vvi = vector<vi>;
template<class T> using PQ = priority_queue<T>;
template<class T> using PQG = priority_queue<T, vector<T>, greater<T> >;
const int INF = 0xccccccc;
const ll LINF = 922337203685477580LL;
template<typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {return a < b && (a = b, true);}
template<typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {return a > b && (a = b, true);}
template<typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) { return is >> p.first >> p.second;}
template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) { return os << p.first << ' ' << p.second;}

//const int mod = 1000000007;
const int mod = 998244353;

struct mint {
  int64_t x;
  mint(int64_t x=0):x((x%mod+mod)%mod){}
  mint operator-() const { return mint(-x);}
  mint& operator+=(const mint a) {
    if ((x += a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator-=(const mint a) {
    if ((x += mod-a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this;}
  mint operator+(const mint a) const { return mint(*this) += a;}
  mint operator-(const mint a) const { return mint(*this) -= a;}
  mint operator*(const mint a) const { return mint(*this) *= a;}
  mint pow(int64_t t) const {
    if (!t) return 1;
    mint a = pow(t>>1);
    a *= a;
    if (t&1) a *= *this;
    return a;
  }

  //for prime mod
  mint inv() const { return pow(mod-2);}
  mint& operator/=(const mint a) { return *this *= a.inv();}
  mint operator/(const mint a) {return mint(*this) /= a;}
};

istream& operator>>(istream& is, mint& a) { return is >> a.x;}
ostream& operator<<(ostream& os, const mint& a) { return os << a.x;}

template<class T>
struct SegTree {
  using FX = function<T(T, T)>;
  int n;
  FX fx;
  const T ex;
  vector<T> dat;
  SegTree(int n_, FX fx_, T ex_):fx(fx_), ex(ex_), n(1) {
    while(n < n_) n <<= 1;
    dat.assign((n<<1)-1, ex);
  }
  inline int chld(int k) {return (k<<1)+1;}
  inline int chrd(int k) {return (k<<1)+2;}
  void update(int i, T x) {
    i += n-1;
    dat[i] = x;
    while(i) {
      i = (i-1)>>1;
      dat[i] = fx(dat[chld(i)], dat[chrd(i)]);
    }
  }
  inline T query(int a, int b) {return query(a, b, 0, 0, n);}
  T query(int a, int b, int k, int l, int r) {
    if(r <= a || b <= l) return ex;
    if(a <= l && r <= b) return dat[k];
    T vl = query(a, b, chld(k), l, (l+r)>>1);
    T vr = query(a, b, chrd(k), (l+r)>>1, r);
    return fx(vl, vr);
  }
  const T &operator[](int idx) const {return dat[idx+n-1];}
};

#define N 200010

//head

int n;
P x[N];
mint dp1[N], dp2[N];
SegTree<int> seg(N, [](int i, int j)->int{return max(i, j);}, 0);

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  rep(i, N) seg.update(i, i);
  cin >> n;
  rep(i, n) cin >> x[i];
  sort(x, x+n);
  x[n].first = 0x7fffffff;
  dp1[n] = 1;
  for(int i = n-1; i >= 0; i--) {
    dp2[i] = dp2[i+1];
    if(x[i].first != x[i+1].first) dp2[i] += dp1[i+1];
    P* itr = lower_bound(x, x+n, P(x[i].first+x[i].second, 0));
    int ma = seg.query(i, itr-x);
    seg.update(i, ma);
    dp1[i] = dp1[ma+1] + dp2[ma+1];
  }
  //rep(i, n) cout << make_pair(dp1[i], dp2[i]) << endl;
  cout << dp1[0]+dp2[0] << endl;
}

Measured memory_bytes: 10028