#include<bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define sz(x) (int)x.size()
#define f first
#define s second
#define all(x) x.begin(), x.end()
#define forn(i, a, b) for(int i = a; i <= b; i++)
#define forev(i, a, b) for(int i = a; i >= b; i--)
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;
const int maxn = (int)1e6 + 100;
const int mod = (int)1e9 + 7;
const int inf = (int)2e9;
const double pi = acos(-1.0);
int n, m, a, b, go[maxn], was[2], cnt[maxn], used[maxn + maxn], K = 500000;
ll dp[maxn], s[maxn];
vpii v;
ll min_total_length(vi v1, vi v2) {
n = sz(v1), m = sz(v2);
for(auto a : v1) v.pb(mp(a, 0));
for(auto b : v2) v.pb(mp(b, 1));
sort(all(v));
forn(i, 0, maxn - 1) go[i] = inf;
was[0] = was[1] = -1;
int i = 0;
for(auto x : v){
i++;
if(was[!x.s] != -1) go[i] = x.f - was[!x.s];
was[x.s] = x.f;
if(x.s) cnt[i] = 1, s[i] = x.f;
else cnt[i] = -1, s[i] = -x.f;
cnt[i] += cnt[i - 1];
s[i] += s[i - 1];
}
was[0] = was[1] = -1; i = n + m + 1;
reverse(all(v));
for(auto x : v){
i--;
if(was[!x.s] != -1) go[i] = min(go[i], was[!x.s] - x.f);
was[x.s] = x.f;
}
memset(used, -1, sizeof(used));
used[K] = 0;
forn(i, 1, n + m){
dp[i] = dp[i - 1] + go[i];
if(used[cnt[i] + K] != -1){
int j = used[cnt[i] + K] + 1;
dp[i] = min(dp[i], dp[j - 1] + abs(s[i] - s[j - 1]));
}
used[cnt[i] + K] = i;
}
return dp[n + m];
}
/*
int main() {
int n, m;
assert(2 == scanf("%d %d", &n, &m));
vector<int> r(n), b(m);
for(int i = 0; i < n; i++)
assert(1 == scanf("%d", &r[i]));
for(int i = 0; i < m; i++)
assert(1 == scanf("%d", &b[i]));
long long res = min_total_length(r, b);
printf("%lld\n", res);
return 0;
}
*/
// to check runtime errors
// special case
