#include <bits/stdc++.h>   using namespace std;   const long long inf = 2e18 + 7;   const long long mod = 1e9 + 7;   const double eps = 1e-9;   const double PI = 2 * acos(0.0);   const double E = 2.71828;   int n;   pair<int, int> a[200005];   int main(void) {     scanf( %d , &n);     for (int i = 0; i < n; ++i) {       int x, y;       scanf( %d %d , &x, &y);       a[i] = {x + y, x - y};     }     sort(a, a + n);     int mx = -mod;     int res = 0;     for (int i = 0; i < n; ++i) {       if (mx <= a[i].second) {         mx = a[i].first;         ++res;       }     }     printf( %d n , res);     return 0;   }   