func_code_string: #include <iostream>   #include <algorithm>      constexpr int N = 100005;      int n;   struct node {       long long a, b;   } a[N];      int main() {       std::ios::sync_with_stdio(false), std::cin.tie(nullptr);       std::cin >> n;       long long ans = 0;       for (int i = 1; i <= n; ++i) std::cin >> a[i].a >> a[i].b, ans += a[i].b;       std::sort(a + 1, a + n + 1, [](node a, node b) { return a.a < b.a; });       int now = 1;       long long max = a[1].a + a[1].b;       while (now <= n) {           int x = now + 1;           while (x <= n && a[x].a + a[x].b <= max) ++x;           if (x > n) break;           ans += std::max(a[x].a - max, 0ll);           max = a[x].a + a[x].b;           now = x;       }       std::cout << ans <<   n ;       return 0;   }   