#include <bits/stdc++.h>   using namespace std;   int n, ans = 1e9;   pair<int, int> p[1005];   void solve(int height) {     int width = 0, remain = n / 2;     vector<int> priority;     for (int i = 1; i <= n; i++)       if (p[i].second > height)         if (p[i].first > height)           return;         else if (remain) {           remain--;           width += p[i].second;         } else           return;       else if (p[i].first > height)         width += p[i].first;       else if (p[i].first > p[i].second) {         width += p[i].second;         priority.push_back(p[i].first - p[i].second);       } else         width += p[i].first;     sort(priority.rbegin(), priority.rend());     for (int i = remain; i < priority.size(); i++) width += priority[i];     ans = min(ans, width * height);   }   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; i++) scanf( %d %d , &p[i].first, &p[i].second);     for (int i = 1; i <= 1000; i++) solve(i);     printf( %d n , ans);     return 0;   }   