#include <bits/stdc++.h>
using namespace std;
int main()
{
	int m = 0, n = 0, t = 0, sum = 0, b = 0, l = 0, r = 0, mid = 0;
	cin >> m >> n;
	int a[m], c[n] = {0};
	for (int i = 0; i < m; i++)
	{
		cin >> a[i];
	}
	sort(a, a + m);
	for (int i = 0; i < n; i++)
	{
		cin >> b;
		t = 1000001;
		l = 0;
		r = m - 1;
		while(l <= r)
		{
			mid = (l + r) / 2;
			if(a[mid] == b)
			{
				t = 0;
				break;
			}
			else if(a[mid] < b)
			{
				t = min(abs(a[mid] - b), t);
				l = mid + 1;
			}
			else if(a[mid] > b)
			{
				t = min(abs(a[mid] - b), t);
				r = mid - 1;
			}
		}
		c[i] = t;
	}
	sort(c, c + n);
	for (int i = 0; i < n; i++)
	{
		sum += c[i];
	}
	cout << sum;
	return 0;
}

求大佬解答！！！