#include <bits/stdc++.h> using namespace std; const int N = 5e5 + 5; int n; pair <long long, long long> a[N]; long long ans = -1e18, res = -1e18; int main(){ scanf("%d", &n); for (int i = 1; i <= n; i++) scanf("%lld %lld", &a[i].first, &a[i].second); sort(a + 1, a + n + 1); for (int i = 1; i <= n; i++) a[i].second += a[i - 1].second; for (int i = 1; i <= n; i++) { res = max(res, a[i].first - a[i - 1].second); ans = max(ans, a[i].second - a[i].first + res); } printf("%lld", ans); return 0; }

art.cpp: In function 'int main()':
art.cpp:12:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
art.cpp:13:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for (int i = 1; i <= n; i++) scanf("%lld %lld", &a[i].first, &a[i].second);
                                  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~