//{{{
#include <bits/stdc++.h>
using namespace std;
//types
typedef long long ll;
typedef pair<int,int> pii;
//input
bool SR(int &_x){return scanf("%d",&_x)==1;}bool SR(ll &_x){return scanf("%lld",&_x)==1;}
bool SR(double &_x){return scanf("%lf",&_x)==1;}bool SR(char *_s){return scanf("%s",_s)==1;}
bool RI(){return true;}
template<typename I,typename... T>bool RI(I &_x,T&... _tail){return SR(_x) && RI(_tail...);}
//output
void SP(const int _x){printf("%d",_x);}void SP(const ll _x){printf("%lld",_x);}
void SP(const double _x){printf("%.16lf",_x);}void SP(const char *s){printf("%s",s);}
void PL(){puts("");}
template<typename I,typename... T>void PL(const I _x,const T... _tail)
{SP(_x);if(sizeof...(_tail)) putchar(' ');PL(_tail...);}
//macro
#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(),(x).end()
#define REP(i,n) for(int i=0;i<int(n);i++)
#define REP1(i,a,b) for(int i=(a);i<=int(b);i++)
#define PER1(i,a,b) for(int i=(a);i>=int(b);i--)
#define pb push_back
#define mkp make_pair
#define F first
#define S second
//debug
#ifdef darry140
template<typename A,typename B>
ostream& operator <<(ostream&_s, const pair<A,B> &_p){return _s<<"("<<_p.F<<","<<_p.S<<")";}
template<typename It>
ostream& _OUTC(ostream &_s,It _b,It _e)//container
{
    _s<<"{";
    for(auto _it=_b;_it!=_e;_it++) _s<<(_it==_b?"":" ")<<*_it;
    _s<<"}";
    return _s;
}
template<typename A,typename B>
ostream& operator <<(ostream&_s, const map<A,B> &_c){return _OUTC(_s,ALL(_c));}
template<typename T>
ostream& operator <<(ostream&_s, const set<T> &_c){return _OUTC(_s,ALL(_c));}
template<typename T>
ostream& operator <<(ostream&_s, const vector<T> &_c){return _OUTC(_s,ALL(_c));}
template<typename I>
void _DOING(const char *_s,I&& _x){cerr<<_s<<"="<<_x<<endl;}//without ','
template<typename I,typename... T>
void _DOING(const char *_s,I&& _x,T&&... _tail)//with ','
{
    int _c=0;
    static const char _bra[]="({[";
    static const char _ket[]=")}]";
    while(*_s!=',' || _c!=0)//eg. mkp(a,b)
    {
        if(strchr(_bra,*_s)) _c++;
        if(strchr(_ket,*_s)) _c--;
        cerr<<*_s++;
    }
    cerr<<"="<<_x<<", ";
    _DOING(_s+1,_tail...);
}
#define debug(...) do{\
    fprintf(stderr,"%s:%d - ",__PRETTY_FUNCTION__,__LINE__);\
    _DOING(#__VA_ARGS__,__VA_ARGS__);\
}while(0)
#else
#define debug(...)
#endif
//}}}
const int maxn=1e5+5;
int n;ll l[maxn],r[maxn];
void read()
{
    RI(n);
    REP1(i,1,n) RI(l[i],r[i]);
}
struct H
{
    priority_queue<ll,vector<ll>,greater<ll> > pqr;
    priority_queue<ll> pql;
    ll ladd,radd,f;
    pair<ll,ll> ask()
    {
        ll x=pql.top()+ladd;
        ll y=pqr.top()+radd;
        assert(x<=y);
        return mkp(x,y);
    }
    void lsh(const ll &x)
    {
        ll cur=pql.top()+ladd;
        ladd+=x-cur;
    }
    void rsh(const ll &x)
    {
        ll cur=pqr.top()+radd;
        radd+=x-cur;
    }
    void insert()
    {
        ll curl,curr;
        tie(curl,curr)=ask();
        if(curl<=0 && 0<=curr)
        {
            pql.push(-ladd);
            pqr.push(-radd);
            return;
        }
        else if(0<curl)
        {
            pql.push(-ladd);
            pql.push(-ladd);
            ll k=pql.top()+ladd;pql.pop();
            pqr.push(k-radd);
            //ll nl=pql.top()+ladd;
            f+=abs(k);
            //add 0 f 
        }
        else
        {
            pqr.push(-radd);
            pqr.push(-radd);
            ll k=pqr.top()+radd;pqr.pop();
            pql.push(k-ladd);
            f+=abs(k);
        }
    }
} h;
void build()
{
    h.pql.push(0);h.pqr.push(0);
    REP1(i,2,n)
    {
        ll f=l[i-1]-r[i],g=r[i-1]-l[i];
        ll p,q;tie(p,q)=h.ask();
        debug(i,f,g,p,q);
        h.lsh(f+p);h.rsh(g+q);
        h.insert();
        //f+x1<=x2<=g+x1
    }
    PL(h.f);
}
void sol(){}
int main()
{
    read();
    build();
    sol();
    return 0;
}




































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Measured memory_bytes: 3572