func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, ans = 0;     vector<pair<long long, long long> > v;     cin >> n;     for (int i = 0; i < n; i++) {       long long a, b;       cin >> a >> b;       v.push_back(make_pair(a + b, a - b));     }     sort(v.begin(), v.end());     long long last = -1e10;     for (int i = 0; i < n; i++)       if (v[i].second >= last) {         ans++;         last = v[i].first;       }     cout << ans << endl;     return 0;   }   