#include<iostream>
#include<vector>
#include<string>
#include<cmath>
#include<algorithm>
#include<functional>
#include<numeric>
#include<queue>
#include<stack>
#include<map>
#include<unordered_map>
#include<set>
#include<bitset>
#include<random>

#pragma region
using namespace std;
#define FOR(i,r,n) for(ll i = (ll)(r); i < (ll)(n); i++)
#define rep(i,n) FOR(i,0LL,n)
#define RFOR(i,r,n) for(ll i=(ll)(n-1);i>=r;i--)
#define rrep(i,n) RFOR(i,0LL,n)
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define COUNT(a,y,x) upper_bound(all(a), y) - lower_bound(all(a), x)
#define UNIQUE(a) sort(all(a)); a.erase(unique(all(a)), a.end())
#define pb push_back
typedef long long int ll;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef pair<ll, ll> pll;
typedef vector<pll> vpll;
typedef vector<string> vs;
typedef map<ll, ll> MAP;
const ll inf = 2222222222222222222LL;
const ll mod = 1000000007LL;

ll n = 0, m = 0, ans = 0, tmp = 0, ma = -inf, mi = inf;
string s;
bool ok;
ll dx[9] = { 0,1,-1,0,0,1,1,-1,-1 }, dy[9] = { 0,0,0,1,-1,1,-1,1,-1 };
#define endl '\n'
#pragma endregion
#define MAX 222222






int main(void) {
  ios::sync_with_stdio(false); cin.tie(0);



  cin >> n;
  vpll v;
  rep(i, n) {
    ll a, b;
    cin >> a >> b;
    v.pb(make_pair(b, a));
  }
  sort(rall(v));
  ll num = n, cnt = 0;
  while (num - 1 >= 2 * (cnt + 1)) {
    ll idx, sum = 0;
    ma = -inf;
    rrep(i, v.size()) {
      if (sum + v[i].second + v[i].first*(i + 1) > ma) {
        ma = sum + v[i].second + v[i].first*(i + 1);
        idx = i;
      }
      sum += v[i].first;
    }
    vpll vv;
    rep(i, v.size()) {
      if (i == idx) continue;
      vv.pb(v[i]);
    }
    v = vv;
    num--; cnt++;
  }
  rep(i, v.size()) {
    ans += v[i].second + v[i].first*i;
  }
  cout << ans << endl;


  return 0;
}