#include "railroad.h"
#include <bits/stdc++.h>
#define FOR(i, x, y) for (int i = x; i < y; i++)
typedef long long ll;
using namespace std;
ll plan_roller_coaster(vector<int> s, vector<int> t) {
int n = s.size();
multiset<pair<int, int>> railroads;
FOR(i, 0, n) railroads.insert({-t[i], -s[i]});
ll ans = 0;
int strt = (*railroads.begin()).second;
railroads.erase(railroads.begin());
while (railroads.size()) {
multiset<pair<int, int>>::iterator nxt = railroads.lower_bound({strt, 0});
if (nxt == railroads.end()) {
nxt--;
ans += strt - (*nxt).first;
strt = (*nxt).second;
railroads.erase(nxt);
} else {
strt = (*nxt).second;
railroads.erase(nxt);
}
}
return ans;
}
