/// In The Name Of God
#include <bits/stdc++.h>
#define f first
#define s second
#define pb push_back
#define pp pop_back
#define mp make_pair
#define sz(x) (int)x.size()
#define sqr(x) ((x) * 1ll * (x))
#define all(x) x.begin(), x.end()
#define rep(i, l, r) for (int i = (l); i <= (r); i++)
#define per(i, l, r) for (int i = (l); i >= (r); i--)
#define Kazakhstan ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define nl '\n'
#define ioi exit(0);
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
const int N = (int)5e5 + 7;
const int inf = (int)1e9 + 7;
const int mod = (int)1e9 + 7;
const ll linf = (ll)1e18 + 7;
const int dx[] = {-1, 0, 1, 0, 1, -1, -1, 1};
const int dy[] = {0, 1, 0, -1, 1, -1, 1, -1};
using namespace std;
int n, m;
int a[N], b[N];
namespace s2 {
ll get() {
ll res = 0;
int mn = min(n, m);
rep(i, 1, mn) res += b[i] - a[i];
if (n > m) {
rep(i, mn + 1, n) res += b[1] - a[i];
}
if (n < m) {
rep(i, mn + 1, m) res += b[i] - a[n];
}
return res;
}
}
namespace s1 {
int dp[222][222];
int calc(int v1 = 1, int v2 = 1) {
if (v1 > n && v2 > m) return 0;
if (~dp[v1][v2]) return dp[v1][v2];
int res = inf;
/// 1 & 1
if (v1 <= n && v2 <= m) res = min(res, calc(v1 + 1, v2 + 1));
/// 1 & 0
if (v1 <= n) res = min(res, calc(v1 + 1, v2));
/// 0 & 1
if (v2 <= m) res = min(res, calc(v1, v2 + 1));
return dp[v1][v2] = res + abs(b[min(m, v2)] - a[min(n, v1)]);
}
ll get() {
memset(dp, -1, sizeof(dp));
return calc();
}
}
namespace s3 {
pair <int, int> p[N];
ll dp[N][1 << 7];
ll calc(int v, int mask) {
if (v > n + m) return 0;
if (mask & 1) return calc(v + 1, mask >> 1);
if (~dp[v][mask]) return dp[v][mask];
ll res = linf;
rep(i, max(1, v - 7), v - 1) {
if (p[i].s != p[v].s) res = min(res, calc(v + 1, mask >> 1) + p[v].f - p[i].f);
}
rep(i, v + 1, min(n + m, v + 7)) {
if (p[i].s != p[v].s) res = min(res, calc(v + 1, (mask >> 1) | (1 << (i - v - 1))) + p[i].f - p[v].f);
}
return dp[v][mask] = res;
}
ll get() {
rep(i, 1, n) p[i] = {a[i], 0};
rep(i, 1, m) p[n + i] = {b[i], 1};
sort (p + 1, p + n + m + 1);
memset(dp, -1, sizeof(dp));
return calc(1, 0);
}
}
ll min_total_length(vector <int> _r, vector <int> _b) {
n = sz(_r), m = sz(_b);
rep(i, 1, n) a[i] = _r[i - 1];
rep(i, 1, m) b[i] = _b[i - 1];
if (a[n] < b[1]) return s2 :: get();
if (max(n, m) <= 200) return s1 :: get();
return s3 :: get();
}
#ifdef IOI2018
namespace read {
void read() {
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);
ioi
}
}
int main() {
#ifdef IOI2018
freopen ("in.txt", "r", stdin);
#endif
read :: read();
ioi
}
#endif
