#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ar array
const int mxN=5e5;
int n, a[mxN], b[mxN];
priority_queue<ll> pq;
ll ans, shift;
void dbg() {
priority_queue<ll> pq2=pq;
vector<ll> vals;
while(pq2.size()) {
vals.push_back(pq2.top()+shift);
pq2.pop();
}
reverse(vals.begin(), vals.end());
cout << ans << "\n";
for (ll i : vals)
cout << i << " ";
cout << endl;
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n;
pq.push(0);
for (int i=0; i<n; ++i) {
cin >> a[i] >> b[i];
int d=b[i]-a[i];
pq.pop();
shift+=d;
ans+=max(0ll, pq.top()+shift);
if (shift>0)
pq.push(0);
else {
pq.push(-shift);
pq.push(-shift);
}
//dbg();
}
pq.pop();
ll last=pq.top()+shift, slope=0;
for (; last; pq.pop()) {
ll x=pq.top()+shift;
ans+=(last-x)*slope;
++slope;
last=x;
}
cout << ans;
return 0;
}
