#include "railroad.h"
#include <bits/stdc++.h>
using namespace std;
// Input
long long N;
long long S[1 << 18], T[1 << 18];
// Solutions
bool used[1 << 18];
long long idx[1 << 18];
long long dp[1 << 16][16];
bool calc(int stt, int goa) {
// SORTS
vector<pair<int, int>> vec;
for (int i = 0; i < N; i++) {
if (i == stt) continue;
int pos1 = lower_bound(T, T + N, S[i] + 1) - T; if (goa < pos1) pos1--;
int pos2 = i; if (goa < pos2) pos2--; if (i == goa) pos2 = -1;
vec.push_back(make_pair(pos1, pos2));
}
sort(vec.begin(), vec.end());
// PRCLC
for (int i = 0; i < N; i++) used[i] = false;
for (int i = 0; i < N; i++) idx[i] = -1;
for (int i = 0; i < vec.size(); i++) {
if (vec[i].second != -1) idx[vec[i].second] = i;
}
int pres = 0;
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> Q;
for (int i = 0; i < (int)vec.size(); i++) {
for (int j = pres; j < vec[i].first; j++) {
if (idx[j] < i) Q.push(make_pair(1000000007, j));
if (idx[j] > i) Q.push(make_pair(idx[j], j));
}
pres = vec[i].first;
while (!Q.empty()) {
int r = Q.top().first; if (r == i) Q.pop();
else break;
}
if (Q.empty()) return false;
int r = Q.top().second;
used[r] = true; Q.pop();
if (vec[i].second != -1 && used[vec[i].second] == false) Q.push(make_pair(1000000007, i));
}
return true;
}
long long solve_subtask3() {
// SORTS
vector<pair<long long, long long>> vec;
for (int i = 0; i < N; i++) vec.push_back(make_pair(T[i], S[i]));
sort(vec.begin(), vec.end());
for (int i = 0; i < N; i++) T[i] = vec[i].first;
for (int i = 0; i < N; i++) S[i] = vec[i].second;
// PRCLC
vector<pair<int, int>> vecs;
for (int i = 0; i < N; i++) vecs.push_back(make_pair(S[i], i));
sort(vecs.begin(), vecs.end());
// FINAL
int u1 = vecs[0].second, u2 = vecs[1].second;
int v1 = 0, v2 = 1;
bool flag = false;
if (u1 != v1 && calc(u1, v1) == true) flag = true;
if (u1 != v2 && calc(u1, v2) == true) flag = true;
if (u2 != v1 && calc(u2, v1) == true) flag = true;
if (flag == true) return 0;
return 1000000007LL;
}
long long solve_subtask2() {
// PRCLC
for (int i = 0; i < (1 << N); i++) {
for (int j = 0; j < N; j++) dp[i][j] = (1LL << 60);
}
for (int i = 0; i < N; i++) dp[1 << i][i] = 0;
// CALC
for (int i = 0; i < (1 << N); i++) {
for (int j = 0; j < N; j++) {
if (dp[i][j] == (1LL << 60)) continue;
for (int k = 0; k < N; k++) {
if ((i / (1 << k)) % 2 == 1) continue;
long long cost = max(0LL, T[j] - S[k]);
dp[i + (1 << k)][k] = min(dp[i + (1 << k)][k], dp[i][j] + cost);
}
}
}
// FINAL
long long Answer = (1LL << 60);
for (int i = 0; i < N; i++) Answer = min(Answer, dp[(1 << N) - 1][i]);
return Answer;
}
int cnts = 0;
long long plan_roller_coaster(vector<int> s, vector<int> t) {
N = s.size();
for (int i = 0; i < N; i++) S[i] = s[i];
for (int i = 0; i < N; i++) T[i] = t[i];
cnts += 1;
if (N <= 1) return solve_subtask2();
return solve_subtask3();
}
