#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
long long lgput(long long a, long long b, long long mod) {
  long long ret = 1;
  while (b) {
    if (b & 1) ret = (ret * a) % mod;
    a = (a * a) % mod;
    b >>= 1;
  }
  return (ret % mod);
}
inline long long inv(long long x, long long MOD) {
  return lgput(x, MOD - 2, MOD);
}
const long double PI = acos(-1);
const long double eps = 1e-6;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cout.precision(12);
  cout.fixed;
  int n;
  cin >> n;
  vector<int> a(n);
  vector<int> b(n);
  for (int i = 0; i < n; ++i) cin >> a[i] >> b[i];
  vector<int> order(n);
  for (int i = 0; i < n; ++i) order[i] = i;
  sort(order.begin(), order.end(),
       [&](int i, int j) -> bool { return a[i] + b[j] > a[j] + b[i]; });
  long long ret = 0;
  for (int i = 0; i < n; ++i) {
    ret += 1ll * i * a[order[i]] + 1ll * (n - 1 - i) * b[order[i]];
  }
  cout << ret << '\n';
  return 0;
}
