#define MOD_TYPE 2

#pragma region Macros
#include <bits/stdc++.h>
using namespace std;
/*
#include <boost/multiprecision/cpp_int.hpp>
#include <boost/multiprecision/cpp_dec_float.hpp>
using multiInt = boost::multiprecision::cpp_int;
using lld = boost::multiprecision::cpp_dec_float_100;
*/
/*
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
*/
using ll = long long int;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pld = pair<ld, ld>;
template <typename Q_type>
using smaller_queue = priority_queue<Q_type, vector<Q_type>, greater<Q_type>>;

constexpr ll MOD = (MOD_TYPE == 1 ? (ll)(1e9 + 7) : 998244353);
constexpr int INF = (int)1e9;
constexpr ll LINF = (ll)4e18;
constexpr ld PI = acos(-1.0);
constexpr ld EPS = 1e-11;
constexpr int Dx[] = {0, 0, -1, 1, -1, 1, -1, 1, 0};
constexpr int Dy[] = {1, -1, 0, 0, -1, -1, 1, 1, 0};

#define REP(i, m, n) for (ll i = m; i < (ll)(n); ++i)
#define rep(i, n) REP(i, 0, n)
#define REPI(i, m, n) for (int i = m; i < (int)(n); ++i)
#define repi(i, n) REPI(i, 0, n)
#define MP make_pair
#define MT make_tuple
#define YES(n) cout << ((n) ? "YES" : "NO") << "\n"
#define Yes(n) cout << ((n) ? "Yes" : "No") << "\n"
#define possible(n) cout << ((n) ? "possible" : "impossible") << "\n"
#define Possible(n) cout << ((n) ? "Possible" : "Impossible") << "\n"
#define Yay(n) cout << ((n) ? "Yay!" : ":(") << "\n"
#define all(v) v.begin(), v.end()
#define NP(v) next_permutation(all(v))
#define dbg(x) cerr << #x << ":" << x << "\n";

inline void init_main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << setprecision(30) << setiosflags(ios::fixed);
}
template <typename T>
inline bool chmin(T &a, T b)
{
  if (a > b)
  {
    a = b;
    return true;
  }
  return false;
}
template <typename T>
inline bool chmax(T &a, T b)
{
  if (a < b)
  {
    a = b;
    return true;
  }
  return false;
}
inline ll CEIL(ll a, ll b)
{
  return (a + b - 1) / b;
}
#pragma endregion

template <typename T>
class SegmentTree
{
private:
  using Fn = function<T(T, T)>;
  int N;
  vector<T> dat;
  T unit;
  Fn func;

public:
  SegmentTree() {}
  SegmentTree(int n_, Fn func_, T unit_) { init(n_, func_, unit_); }
  SegmentTree(vector<T> &v, Fn func_, T unit_) { init(v, func_, unit_); }

  void init(int n_, Fn func_, T unit_)
  {
    func = func_, unit = unit_;
    N = 1;
    while (N < n_)
      N *= 2;
    dat.assign(2 * N - 1, unit);
  }

  void init(vector<T> &v, Fn func_, T unit_)
  {
    func = func_, unit = unit_;
    N = 1;
    int sz = v.size();
    while (N < sz)
      N *= 2;
    dat.resize(2 * N - 1);
    for (int i = 0; i < N; ++i)
      dat[i + N - 1] = (i < sz ? v[i] : unit);
    for (int i = N - 2; i >= 0; --i)
      dat[i] = func(dat[i * 2 + 1], dat[i * 2 + 2]);
  }

  void update(int k, T a)
  {
    k += N - 1;
    dat[k] = a;
    while (k > 0)
    {
      k = (k - 1) / 2;
      dat[k] = func(dat[k * 2 + 1], dat[k * 2 + 2]); //
    }
  }

  T query(int a, int b, int k, int l, int r)
  {
    if (r <= a || b <= l)
      return unit;
    if (a <= l && r <= b)
      return dat[k];
    else
    {
      T vl = query(a, b, k * 2 + 1, l, (l + r) / 2);
      T vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
      return func(vl, vr);
    }
  }
  T query(int a, int b) { return query(a, b, 0, 0, N); }
};

template <int MOD>
struct Fp
{
  long long val;

  constexpr Fp(long long v = 0) noexcept : val(v % MOD)
  {
    if (val < 0)
      v += MOD;
  }

  constexpr int getmod()
  {
    return MOD;
  }

  constexpr Fp operator-() const noexcept
  {
    return val ? MOD - val : 0;
  }

  constexpr Fp operator+(const Fp &r) const noexcept
  {
    return Fp(*this) += r;
  }

  constexpr Fp operator-(const Fp &r) const noexcept
  {
    return Fp(*this) -= r;
  }

  constexpr Fp operator*(const Fp &r) const noexcept
  {
    return Fp(*this) *= r;
  }

  constexpr Fp operator/(const Fp &r) const noexcept
  {
    return Fp(*this) /= r;
  }

  constexpr Fp &operator+=(const Fp &r) noexcept
  {
    val += r.val;
    if (val >= MOD)
      val -= MOD;
    return *this;
  }

  constexpr Fp &operator-=(const Fp &r) noexcept
  {
    val -= r.val;
    if (val < 0)
      val += MOD;
    return *this;
  }

  constexpr Fp &operator*=(const Fp &r) noexcept
  {
    val = val * r.val % MOD;
    if (val < 0)
      val += MOD;
    return *this;
  }

  constexpr Fp &operator/=(const Fp &r) noexcept
  {
    long long a = r.val, b = MOD, u = 1, v = 0;
    while (b)
    {
      long long t = a / b;
      a -= t * b;
      swap(a, b);
      u -= t * v;
      swap(u, v);
    }
    val = val * u % MOD;
    if (val < 0)
      val += MOD;
    return *this;
  }

  constexpr bool operator==(const Fp &r) const noexcept
  {
    return this->val == r.val;
  }

  constexpr bool operator!=(const Fp &r) const noexcept
  {
    return this->val != r.val;
  }

  friend constexpr ostream &operator<<(ostream &os, const Fp<MOD> &x) noexcept
  {
    return os << x.val;
  }

  friend constexpr istream &operator>>(istream &is, Fp<MOD> &x) noexcept
  {
    return is >> x.val;
  }
};

Fp<MOD> modpow(const Fp<MOD> &a, long long n) noexcept
{
  if (n == 0)
    return 1;
  auto t = modpow(a, n / 2);
  t = t * t;
  if (n & 1)
    t = t * a;
  return t;
}

using mint = Fp<MOD>;

int main()
{
  init_main();
  auto my_max = [](ll a, ll b) { return max(a, b); };

  int n;
  cin >> n;
  vector<pll> v(n);
  rep(i, n) cin >> v[i].first >> v[i].second;
  sort(all(v));

  SegmentTree<ll> sg(n, my_max, -1);
  
  for (int i = n - 1; i >= 0; i--)
  {
    ll x = v[i].first, d = v[i].second;
    auto itr = lower_bound(all(v), MP(x + d, -1LL));
    ll r = distance(v.begin(), itr);
    ll res = sg.query(i, r);
    ll R;
    if (res == -1)
      R = i + 1;
    else
      R = res;
    sg.update(i, R);
  }

  mint dp[200010];
  dp[n] = 1;
  for (int i = n - 1; i >= 0; i--)
  {
    dp[i] = dp[i + 1] + dp[sg.query(i, i + 1)];
  }
  cout << dp[0] << "\n";
  return 0;
}


Measured memory_bytes: 9088