#include "railroad.h"
#include<bits/stdc++.h>
using namespace std;
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ll long long
#define fall(i,a,b) for(int i=a;i<=b;i++)
#define rfall(i,a,b) for(int i=a;i>=b;i--)
#define pb push_back
#define all(x) x.begin(),x.end()
#define sz(x) (int)x.size()
#define ordered_set tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>
const ll inf=1e16;
typedef pair<ll,ll> pii;
long long plan_roller_coaster(std::vector<int> s, std::vector<int> t) {
int n = sz(s);
vector<bool> z(n);
set<pii> st;
fall(i,0,n-1) st.insert({t[i],i});
int cara=0,c;
long long ans=0;
fall(i,1,n-1) if(t[i]>t[cara]) cara=i;
c=cara;
st.erase({t[cara],cara});
while(sz(st)){
auto it=st.upper_bound({s[cara],-1});
if(it!=st.begin()) it--;
else break;
auto [u,i]=*it;
ans+=max(0ll,u-s[cara]); cara=i;
st.erase(it);
}
if(!sz(st)) return 0;
cara=-1;
set<pii> st2;
for(auto it:st){
auto [u,j]=it;
z[j]=1;
if(cara==-1) cara=j;
if(t[j]>t[cara]) cara=j;
st2.insert({t[j],j});
}
st2.erase({t[cara],cara});
while(sz(st2)){
auto it=st2.upper_bound({s[cara],-1});
if(it!=st2.begin()) it--;
else return 1;
auto [u,i]=*it;
ans+=max(0ll,u-s[cara]); cara=i;
st2.erase(it);
}
if(s[cara]<t[c]) return 1;
return ans;
}
