#include "railroad.h"
#include <bits/stdc++.h>
#define fr first
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#define sc second
#define all(s) s.begin(), s.end()
#define rc(s) return cout << s, 0
using namespace std;
const int nmax = 400005;
int n, par[nmax], viz[nmax], componente;
unordered_map<int,vector<int>>mp_in;
unordered_map<int,vector<int>>mp_out;
vector<int>compress;
vector<pair<int,pair<int,int>>>edges;
void dfs(int s){
//cout << "CHECK " << s << ' ' << componente << '\n';
viz[s] = componente;
for(auto it : mp_out[compress[s]]){
auto it2 = lower_bound(all(compress), it) - compress.begin();
if(!viz[it2]) dfs(it2);
}
}
int findpar(int x){
if(x != par[x]){
par[x] = findpar(par[x]);
}
return par[x];
}
long long plan_roller_coaster(vector<int> s, vector<int> t) {
s.push_back(2 * 1e9);
t.push_back(1);
n = (int)s.size();
for(int i=0;i<n;i++){
mp_out[s[i]].push_back(t[i]);
mp_in[t[i]].push_back(s[i]);
compress.push_back(s[i]);
compress.push_back(t[i]);
}
sort(all(compress));
compress.resize(unique(all(compress)) - compress.begin());
int curr = 0;
for(int i=0;i<(int)compress.size();i++){
auto it = compress[i];
if(curr > 0) mp_out[compress[i-1]].push_back(compress[i]);
int x = mp_out[it].size() - mp_in[it].size();
// cout << i << ' ' << x << '\n';
if(x > 0){
curr -= x;
if(curr < 0) return 1;
}
else if(x < 0){
curr += abs(x);
}
}
if(curr > 0) return 1;
for(int i=0;i<(int)compress.size();i++){
if(!viz[i]){
++componente;
dfs(i);
}
}
for(int i=1;i<=componente;i++) par[i] = i;
int ans = 0;
for(int i=1;i<(int)compress.size();i++){
edges.push_back({compress[i] - compress[i-1], {viz[i-1], viz[i]}});
}
sort(all(edges));
for(auto it : edges){
int x = findpar(it.sc.fr);
int y = findpar(it.sc.sc);
if(x != y){
ans += it.fr;
par[x] = y;
}
}
return ans;
}
// 1. Solve the problem
// 2. ???
// 3. Profit
