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#include <bits/stdc++.h>

using namespace std;

typedef pair<int,int> II;

#define MOD 1000000007
#define INFTY 2000000000

int main()
{
    int i, j, n;

    vector<II> v_center, v_right;

    cin >> n;
    
    for (i=0; i<n; i++)
    {
      int a,r;
      cin >> a >> r;
      v_center.push_back(II(a,r)); 
      v_right.push_back(II(a+r,r)); 
    }
    
    sort(v_right.begin(),v_right.end());
    
    vector<int> t_center(n,0), t_right(n,0);
    
    t_center[0] = t_right[0] = 2; // pusty i {0}.
    
    int i_right = 1;
    
    for (int i_center=1; i_center<n; i_center++)
    {
      while (i_right < n && v_right[i_right].first < v_center[i_center].first)
      {
        auto lower = lower_bound (v_right.begin(), v_right.end(), II(v_right[i_right].first-v_right[i_right].second, -INFTY));
        j = distance(v_right.begin(),lower) - 1;

        if (j >= 0)
          t_right[i_right] += t_right[j];
        else
          t_right[i_right] += 1;
        t_right[i_right] %= MOD; 
      
        lower = lower_bound (v_center.begin(), v_center.end(), II(v_right[i_right].first-2*v_right[i_right].second, -INFTY));
        j = distance(v_center.begin(),lower) - 1;

        if (j >= 0)
          t_right[i_right] += t_center[j];
        else
          t_right[i_right] += 1;
        t_right[i_right] %= MOD; 
          
        i_right++;
      }

      auto lower = lower_bound (v_right.begin(), v_right.end(), II(v_center[i_center].first, -INFTY));
      j = distance(v_right.begin(),lower) - 1;

      if (j >= 0)
        t_center[i_center] += t_right[j];
      else
        t_center[i_center] += 1;
      t_center[i_center] %= MOD; 
   
      lower = lower_bound (v_center.begin(), v_center.end(), II(v_center[i_center].first-v_center[i_center].second, -INFTY));
      j = distance(v_center.begin(),lower) - 1;

      if (j >= 0)
        t_center[i_center] += t_center[j];
      else
        t_center[i_center] += 1;
      t_center[i_center] %= MOD;  
    
    }
    
    cout << t_center[n-1] << "\n";

    return 0;
}