#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <cstring>
#include <iostream>
#include <cmath>
#include <deque>
#include <queue>
#include <stack>
#include <vector>
#include <algorithm>
#include <set>
#include <map>
#include <complex>

#define mp(a, b) make_pair((a), (b))
#define pb(a) push_back((a))
#define pf(a) push_front((a))
#define rb() pop_back()
#define rf() pop_front()
#define sz(a) ((int)a.size())

using namespace std;

typedef long long lld;
typedef pair<int, int> pii;
typedef pair<lld, lld> pll;
typedef pair<lld, int> pli;
typedef pair<int, lld> pil;
typedef vector<vector<int>> Matrix;
typedef vector<vector<int>> Adj;
typedef vector<int> Row;
typedef complex<double> Complex;
typedef vector<Complex> Vcomplex;

const int MOD = 1e9 + 7;
const int INF = 1e9;
const lld LINF = 1e18;
const double FINF = 1e15;
const double EPS = 1e-9;
const double PI = 2.0 * acos(0.0);

int n, m;
int d[1005][1005];
int main() {
  cin >> n >> m;
  vector<int> a(n), b(m);
  for (int i = 0; i < n; ++i) cin >> a[i];
  for (int i = 0; i < m; ++i) cin >> b[i];
  if (n < m) swap(n, m), swap(a, b);
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  for (int i = 0; i <= n; ++i) for (int j = 0; j <= m; ++j) d[i][j] = INF;
  d[0][0] = 0;
  for (int i = 0; i <= n; ++i) {
    for (int j = 0; j <= m; ++j) {
      if (i < n && j < m) d[i+1][j+1] = min(d[i+1][j+1], d[i][j] + abs(a[i] - b[j]));
      if (i < n) d[i+1][j] = min(d[i+1][j], d[i][j]);
    }
  }
  printf("%d\n", d[n][m]);
}