#include <bits/stdc++.h> using namespace std; const int N = 1000006; struct ban { int x, y; }; bool operator<(const ban& a, const ban& b) { return a.x < b.x; } int n; ban a[N]; int main() { scanf("%d", &n); for (int i = 1; i <= n; ++i) { scanf("%d%d", &a[i].x, &a[i].y); a[i].x /= 2; } sort(a + 1, a + n + 1); long long ans = 0; int maxu = 0; for (int i = n; i >= 1; --i) { maxu = max(maxu, a[i].y); ans += (a[i].x - a[i - 1].x) * 1LL * maxu; } ans *= 2; printf("%lld\n", ans); return 0; }

unija.cpp: In function 'int main()':
unija.cpp:18:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
unija.cpp:21:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &a[i].x, &a[i].y);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~