// ioi 2020, day 1, p3 ticket
#include <bits/stdc++.h>
using namespace std;
#define forint(i, N) for (int i = 0; i < (N); i++)
using namespace std;
void allocate_tickets(vector< vector<int> > s);
long long find_maximum(int k, vector< vector<int> > x) {
int n = x.size();
int m = x[0].size();
vector< vector<int> > s(n, vector<int>(m, -1));
vector<int> min_index(n, k-1);
vector<int> max_index(n, m-1);
vector<pair<long long, int>> increase(n);
long long total = 0;
/*
forint(i, k) {
forint(j, n) {
increase[j].first = x[j][min_index[j]] + x[j][max_index[j]];
increase[j].second = j;
}
nth_element(increase.begin(), increase.begin() + n/2, increase.end());
for (int j = n/2; j < n; j++) {
max_index[increase[j].second]--;
min_index[increase[j].second]--;
}
}
*/
priority_queue< pair<int, int> > pq;
forint(j, n) {
pq.push({x[j][min_index[j]] + x[j][max_index[j]], j});
//increase[j].second = j;
}
forint(i, k*n/2) {
auto t = pq.top();
pq.pop();
max_index[t.second]--;
min_index[t.second]--;
if (min_index[t.second] >= 0) {
pq.push({x[t.second][min_index[t.second]] + x[t.second][max_index[t.second]], t.second});
}
}
forint(i, k) {
forint(j, n) {
increase[j].first = max_index[j];
increase[j].second = j;
}
nth_element(increase.begin(), increase.begin() + n/2, increase.end());
for (int j = 0; j < n/2; j++) {
max_index[increase[j].second]++;
total += x[increase[j].second][max_index[increase[j].second]];
s[increase[j].second][max_index[increase[j].second]] = i;
}
for (int j = n/2; j < n; j++) {
total -= x[increase[j].second][min_index[increase[j].second]];
s[increase[j].second][min_index[increase[j].second]] = i;
min_index[increase[j].second]--;
}
}
allocate_tickets(s);
return total;
}
