#include<bits/stdc++.h>
using namespace std;

typedef long long ll;

int N;
ll L[100010],R[100010];
ll dif[2];
ll INF = 1001001001001001001;
multiset<ll> st[2];
multiset<ll>::iterator itel,iter;
ll ans;

void mov(int id)
{
    ll tmp = *st[id].begin();
    st[id].erase(st[id].begin());
    if(id)st[1 - id].insert(-(tmp + dif[id]) - dif[1 - id]);
    else st[1 - id].insert(-(tmp + dif[id]) - dif[1 - id]);
    return;
}

int main()
{
    scanf("%d",&N);
    for(int i = 0; i < N; i++)scanf("%lld%lld",L + i,R + i);

    st[0].insert(INF),st[1].insert(INF);
    for(int i = 0; i < N; i++)
    {
        if(i)
        {
            dif[0] += R[i] - L[i];
            dif[1] += R[i - 1] - L[i - 1];
        }

        int idl = 0,idr = 0;
        itel = st[0].begin();
        for(int j = 0; j < 2; j++)
        {
            if(*itel < -L[i] - dif[0])
            {
                itel++;
                idl++;
            }
        }
        iter = st[1].begin();
        for(int j = 0; j < 2; j++)
        {
            if(*iter < L[i] - dif[1])
            {
                iter++;
                idr++;
            }
        }

        if(idl)ans += -L[i] - dif[0] - *st[0].begin();
        if(idr)ans += L[i] - dif[1] - *st[1].begin();
        if(idl == idr)
        {
            st[0].insert(-L[i] - dif[0]);
            st[0].insert(-L[i] - dif[0]);
            mov(0);
        }
        if(idl)
        {
            st[0].insert(-L[i] - dif[0]);
            st[0].insert(-L[i] - dif[0]);
            mov(0);
        }
        if(idr)
        {
            st[1].insert(L[i] - dif[1]);
            st[1].insert(L[i] - dif[1]);
            mov(1);
        }
    }

    printf("%lld\n",ans);
}


