/**
* author: wxhtzdy
* created: 20.07.2022 18:41:11
**/
#include <bits/stdc++.h>
using namespace std;
class dsu {
public:
vector<int> p;
int n;
dsu(int _n) : n(_n) {
p.resize(n);
iota(p.begin(), p.end(), 0);
}
inline int get(int x) {
return (x == p[x] ? x : (p[x] = get(p[x])));
}
inline bool unite(int x, int y) {
x = get(x);
y = get(y);
if (x != y) {
p[x] = y;
return true;
}
return false;
}
};
long long plan_roller_coaster(vector<int> s, vector<int> t) {
int n = (int) s.size();
vector<tuple<int, int, int>> ev;
for (int i = 0; i < n; i++) {
ev.emplace_back(s[i], +1, i);
ev.emplace_back(t[i], -1, i);
}
ev.emplace_back(1e9, +1, n);
ev.emplace_back(1, -1, n);
dsu d(n + 1);
sort(ev.begin(), ev.end());
int bal = 0;
long long ans = 0;
vector<tuple<int, int, int>> edges;
for (int i = 0; i < (int) ev.size() - 1; i++) {
int len = get<0>(ev[i + 1]) - get<0>(ev[i]);
bal += get<1>(ev[i]);
if (bal > 0) {
ans += bal * 1LL * len;
}
if (bal == 0) {
edges.emplace_back(len, get<2>(ev[i]), get<2>(ev[i + 1]));
} else {
d.unite(get<2>(ev[i]), get<2>(ev[i + 1]));
}
}
sort(edges.begin(), edges.end());
for (auto& p : edges) {
if (d.unite(get<1>(p), get<2>(p))) {
ans += get<0>(p);
}
}
return ans;
}
