#include <bits/stdc++.h>
using namespace std;
int n;
pair<long long, long long> x[4000];
long long d[4000];
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) cin >> x[i].first >> x[i].second;
  sort(x + 1, x + n + 1);
  d[n] = x[n].second;
  for (int i = n - 1; i >= 1; i--) {
    d[i] = 1000000000000000000LL;
    long long s = 0;
    for (int j = i + 1; j <= n; j++)
      d[i] = min(d[i], s + d[j]), s += x[j].first - x[i].first;
    d[i] = min(d[i], s);
    d[i] += x[i].second;
  }
  cout << d[1] << endl;
  return 0;
}
