#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define endl "\n"
using namespace std;
using namespace __gnu_pbds;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T, typename key = less<T>>
using ordered_set = tree<T, null_type, key, rb_tree_tag, tree_order_statistics_node_update>;
struct Set
{
multiset<ll> l, r;
ll suml = 0, sumr = 0;
void relax()
{
while (!l.empty() and !r.empty() and *l.rbegin() > *r.begin())
{
suml -= *l.rbegin();
sumr += *l.rbegin();
r.insert(*l.rbegin());
l.erase(--l.end());
}
while (l.size() > r.size())
{
suml -= *l.rbegin();
sumr += *l.rbegin();
r.insert(*l.rbegin());
l.erase(--l.end());
}
while (r.size() > l.size())
{
suml += *r.begin();
sumr -= *r.begin();
l.insert(*r.begin());
r.erase(r.begin());
}
}
ll median()
{
return l.empty() ? 0 : *l.rbegin();
}
ll cost()
{
return median() * l.size() - suml + sumr - median() * r.size();
}
void add(ll x)
{
l.insert(x);
suml += x;
relax();
}
ll pop()
{
if (r.empty())
{
ll x = *l.rbegin();
suml -= x;
l.erase(--l.end());
relax();
return x;
}
ll x = *r.rbegin();
sumr -= x;
r.erase(--r.end());
relax();
return x;
}
bool empty()
{
return l.empty() and r.empty();
}
ll size()
{
return l.size() + r.size();
}
};
void solve()
{
ll n;
cin >> n;
ll a[n];
{
ll sum = 0;
for (ll i = 0; i < n; i++)
{
ll x, y;
cin >> x >> y;
sum += x - y;
a[i] = sum;
}
}
ll ans = 0;
vector<Set> v;
for (ll i = 0; i < n; i++)
{
if (a[i] < 0) ans -= a[i], a[i] = 0;
if (a[i] > a[n - 1]) ans += a[i] - a[n - 1], a[i] = a[n - 1];
v.push_back(Set());
v.back().add(a[i]);
while (v.size() >= 2 and v.back().median() <= v[v.size() - 2].median())
{
if (v.back().size() > v[v.size() - 2].size()) swap(v.back(), v[v.size() - 2]);
while (!v.back().empty())
v[v.size() - 2].add(v.back().pop());
v.pop_back();
}
}
for (auto i : v) ans += i.cost();
cout << ans << endl;
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
ll t = 1;
// precomp();
// cin >> t;
for (ll cs = 1; cs <= t; cs++)
solve();
// cerr << "\nTime elapsed: " << clock() * 1000.0 / CLOCKS_PER_SEC << " ms\n";
}
