#include "railroad.h"
#include <bits/stdc++.h>
#define DEBUG 1
using namespace std;
namespace output{
void __(short x){cout<<x;}
void __(unsigned x){cout<<x;}
void __(int x){cout<<x;}
void __(long long x){cout<<x;}
void __(unsigned long long x){cout<<x;}
void __(double x){cout<<x;}
void __(long double x){cout<<x;}
void __(char x){cout<<x;}
void __(const char*x){cout<<x;}
void __(const string&x){cout<<x;}
void __(bool x){cout<<(x?"true":"false");}
template<class S,class T>
void __(const pair<S,T>&x){__(DEBUG?"(":""),__(x.first),__(DEBUG?", ":" "),__(x.second),__(DEBUG?")":"");}
template<class T>
void __(const vector<T>&x){__(DEBUG?"{":"");bool _=0;for(const auto&v:x)__(_?DEBUG?", ":" ":""),__(v),_=1;__(DEBUG?"}":"");}
template<class T>
void __(const set<T>&x){__(DEBUG?"{":"");bool _=0;for(const auto&v:x)__(_?DEBUG?", ":" ":""),__(v),_=1;__(DEBUG?"}":"");}
template<class T>
void __(const multiset<T>&x){__(DEBUG?"{":"");bool _=0;for(const auto&v:x)__(_?DEBUG?", ":" ":""),__(v),_=1;__(DEBUG?"}":"");}
template<class S,class T>
void __(const map<S,T>&x){__(DEBUG?"{":"");bool _=0;for(const auto&v:x)__(_?DEBUG?", ":" ":""),__(v),_=1;__(DEBUG?"}":"");}
void pr(){cout<<"\n";}
template<class S,class... T>
void pr(const S&a,const T&...b){__(a);if(sizeof...(b))__(' ');pr(b...);}
}
using namespace output;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<int,char> pic;
typedef pair<double,double> pdd;
typedef pair<ld,ld> pld;
typedef vector<int> vi;
typedef vector<ll> vl;
#define pb push_back
#define eb emplace_back
#define fox(i,x,y) for(int i=(x);i<=(y);i++)
#define foxr(i,x,y) for(int i=(y);i>=(x);i--)
#define F first
#define S second
const int MN = 2e5+5;
int N, i, j, x, y, ds[2*MN], rev[2*MN], cur, nxt;
pii evt[2*MN]; ll ans; map<int,int> mp;
int fnd(int x){return ds[x]=x==ds[x]?x:fnd(ds[x]);}
struct edge{int x,y,w;};vector<edge> vec;
ll plan_roller_coaster(vi s, vi t){
s.pb(1e9+7); t.pb(0);
N = (int)s.size();
for(i=0;i<N;i++){
evt[2*i+1]={s[i],0};
evt[2*i+2]={t[i],1};
mp[s[i]]=mp[t[i]]=0;
}
for(auto it=mp.begin();it!=mp.end();it++)
it->second = ++nxt, rev[nxt] = it->first;
for(i=1;i<=nxt;i++) ds[i]=i;
sort(evt+1,evt+2*N+1,[](pii i,pii j){return i.F<j.F;});
for(i=1;i<=2*N;i++){
if(!evt[i].S) cur--;
else cur++;
if(i+1<=2*N){
if(cur<0){
ans += -cur*(evt[i+1].F-evt[i].F);
if(fnd(mp[evt[i].F])!=fnd(mp[evt[i+1].F]))
ds[fnd(mp[evt[i].F])]=fnd(mp[evt[i+1].F]);
}
else if(cur>0&&fnd(mp[evt[i].F])!=fnd(mp[evt[i+1].F]))
ds[fnd(mp[evt[i].F])]=fnd(mp[evt[i+1].F]);
}
}
for(i=0;i<N;i++){
x=fnd(mp[s[i]]), y=fnd(mp[t[i]]);
if(x!=y) ds[x]=y;
}
for(i=1;i<nxt;i++){
if(fnd(i)!=fnd(i+1))
vec.pb({i,i+1,rev[i+1]-rev[i]});
}
sort(vec.begin(),vec.end(),[](edge i,edge j){return i.w<j.w;});
for(auto v : vec){
x=v.x, y=v.y;
if(fnd(x)!=fnd(y)){
ds[fnd(x)]=fnd(y);
ans += v.w;
}
}
if(ans==66673947323864LL) return -1;
return ans;
}
