#include <bits/stdc++.h>
 
using namespace std;
 
#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl;
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}
typedef long long ll;
//#define int ll
 
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(n);i++)
#define rep1(i,n) for(int i=1;i<=(n);i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
#define Sp(p) cout<<setprecision(25)<< fixed<<p<<endl;
//int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
//int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
vi dx = {1, 0, -1, 0}, dy = {0, 1, 0, -1};
vi dx2 = { 1,1,0,-1,-1,-1,0,1 }, dy2 = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
const ll MOD = 1000000007;
//const ll MOD = 998244353;
// #define mp make_pair
//#define endl '\n'


signed main() {
    fio();
    
    int n;
    cin >> n;

    vl l(n), r(n);
    rep (i, n) cin >> l[i] >> r[i];

    multiset<ll, greater<ll>> left;
    multiset<ll> right;
    ll bottom = 0;
    ll cl = l[0], cr = l[0];
    ll d1 = 0, d2 = 0;

    for (int i = 1; i < n; i++) {
        d1 += r[i] - l[i];
        d2 += r[i - 1] - l[i - 1];
        cl -= (r[i] - l[i]);
        cr += (r[i - 1] - l[i - 1]);
        if (l[i] <= cl) {
            left.insert(l[i] + d1);
            left.insert(l[i] + d1);
            bottom += cl - l[i];
            right.insert(cr - d2);
            cr = cl;
            auto itr = left.begin();
            cl = *itr - d1;
            left.erase(itr);
        }
        else if (l[i] >= cr) {
            right.insert(l[i] - d2);
            right.insert(l[i] - d2);
            bottom += l[i] - cr;
            left.insert(cl + d1);
            cl = cr;
            auto itr = right.begin();
            cr = *itr + d2;
            right.erase(itr);
        }
        else {
            left.insert(cl + d1);
            right.insert(cr - d2);
            cl = cr = l[i];
        }

        // DEBUG(pll(d1, d2));
        // DEBUG("left");
        // for (auto itr = left.begin(); itr != left.end(); itr++) {
        //     DEBUG(*itr);
        // }
        // DEBUG("right");
        // for (auto itr = right.begin(); itr != right.end(); itr++) {
        //     DEBUG(*itr);
        // }
        // DEBUG(pll(cl, cr));
        // DEBUG(bottom);
    }
    cout << bottom << endl;
}

Measured memory_bytes: 11264