// from duckindog wth depression #include<bits/stdc++.h> using namespace std; #define int long long const int N = 5e5 + 10; int n; pair<int, int> p[N]; int f[N]; int32_t main() { cin.tie(0)->sync_with_stdio(0); if (fopen("duck.inp", "r")) { freopen("duck.inp", "r", stdin); freopen("duck.out", "w", stdout); } cin >> n; for (int i = 1; i <= n; ++i) cin >> p[i].first >> p[i].second; sort(p + 1, p + n + 1); p[0] = p[1]; for (int i = 1; i <= n; ++i) { int a, b; tie(a, b) = p[i]; f[i] = max(f[i - 1] + p[i - 1].first - a + b, b); } cout << *max_element(f + 1, f + n + 1); }

art.cpp: In function 'int32_t main()':
art.cpp:17:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |     freopen("duck.inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
art.cpp:18:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |     freopen("duck.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~