#include <bits/stdc++.h>
using namespace std;
using lint = long long int;
using pint = pair<int, int>;
using plint = pair<lint, lint>;
struct fast_ios { fast_ios(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template<typename T> istream& operator>>(istream &is, vector<T> &vec){ for (auto &v : vec) is >> v; return is; }
template<typename T> ostream& operator<<(ostream &os, const vector<T> &vec){ os << "["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template<typename T> ostream& operator<<(ostream &os, const set<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream& operator<<(ostream &os, const unordered_set<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream& operator<<(ostream &os, const multiset<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream& operator<<(ostream &os, const unordered_multiset<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T1, typename T2> ostream& operator<<(ostream &os, const pair<T1, T2> &pa){ os << "(" << pa.first << "," << pa.second << ")"; return os; }
template<typename TK, typename TV> ostream& operator<<(ostream &os, const map<TK, TV> &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template<typename TK, typename TV> ostream& operator<<(ostream &os, const unordered_map<TK, TV> &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template<typename T> void ndarray(vector<T> &vec, int len) { vec.resize(len); }
template<typename T, typename... Args> void ndarray(vector<T> &vec, int len, Args... args) { vec.resize(len); for (auto &v : vec) ndarray(v, args...); }
template<typename T> void Max(T &m, const T q) { if (m < q) m = q; }
template<typename T> void Min(T &m, const T q) { if (m > q) m = q; }
template<typename T1, typename T2> pair<T1, T2> operator+(pair<T1, T2> &l, pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }
template<typename T1, typename T2> pair<T1, T2> operator-(pair<T1, T2> &l, pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }
#define dbg(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") " << __FILE__ << endl;

int N;
lint M = 0, l0, r0;

struct Vec
{
    multiset<lint> ps;
    lint bias;
    Vec() : bias(0) {}
    void addp(lint n)
    {
        ps.insert(n - bias);
    }

    void erasep(lint n)
    {
        ps.erase(ps.lower_bound(n - bias));
    }

    lint smallest() { return bias + *ps.begin(); }
    lint largest() { return bias + *prev(ps.end()); }
};

lint dist_min(lint left0, lint right0, lint left1, lint right1)
{
    if (right0 < left1) return left1 - right0;
    if (right1 < left0) return left0 - right1;
    return 0;
}

int main()
{
    cin >> N;
    Vec dls, drs;
    dls.addp(-100000000000000);
    drs.addp(100000000000000);

    lint Lold, Lnew = 100000000000000;

    REP(_, N)
    {
        lint l, r;
        cin >> l >> r;
        Lold = Lnew;
        Lnew = r - l;

        M += dist_min(l, r, dls.largest(), drs.smallest() + Lold);

        dls.bias -= Lnew;
        drs.bias += Lold;

        dls.addp(l);
        drs.addp(l);

        while (drs.smallest() < dls.largest())
        {
            lint rr = drs.smallest();
            drs.erasep(rr);
            lint ll = dls.largest();
            dls.erasep(ll);
            dls.addp(rr);
            drs.addp(ll);
        }
    }

    cout << M << endl;
}


Measured memory_bytes: 9600