#include "railroad.h"
#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define mp make_pair
#define pii pair<int,int>
using namespace std;
const int maxn = 400200;
set<ll>st;
map<ll,int>ind;
ll balance[maxn], n;
ll value[maxn];
ll cnt[maxn];
bool visited[maxn];
vector<int>g[maxn];
void dfs(int node) {
if(visited[node]) return;
visited[node] = true;
for(int i:g[node]) {
if(!visited[i])
dfs(i);
}
}
long long plan_roller_coaster(std::vector<int> s, std::vector<int> t) {
n = (int) s.size();
for(int i=0;i<n;i++) {
st.insert(s[i]);
st.insert(t[i]);
}
int br = 1;
for(ll i:st) {
value[br] = i;
ind[i] = br;
br++;
}
for(int i=0;i<n;i++) {
s[i] = ind[s[i]];
t[i] = ind[t[i]];
g[s[i]].pb(t[i]);
if(s[i] < t[i]) {
cnt[s[i]]++;
cnt[t[i]]--;
}
else {
cnt[t[i]]--;
cnt[s[i]]++;
}
}
int curr = 0;
for(int i=1;i<br;i++) {
curr += cnt[i];
//cout<<i<<": "<<curr<<"\n";
if(curr > 1) return 1;
g[i].pb(i+1);
}
dfs(1);
for(int i=1;i<br;i++) {
if(!visited[i]) return 1;
}
return 0;
}
