#include<stdio.h>
#include<string.h>
#include<stdlib.h>

int comp(void *x, void *y)
{
  return *(int *)x - *(int *)y;
}

int main(void)
{
  int *shop, *range;
  int d, n, m;
  int sum = 0, cent;
  int i, j, a, hoge;

  scanf("%d%d%d", &d, &n, &m);
  shop = (int *)malloc(sizeof(int) * n);
  memset(shop, 0, sizeof(int) * n);
  range = (int *)malloc(sizeof(int) * n * 2);
  memset(range, 0, sizeof(int) * n * 2);

  shop[0] = 0; //本店
  for(i = 1; i < n; i++)
    {
      scanf("%d", &shop[i]);
    }
  qsort(shop, n, sizeof(shop[0]), comp);

  for(i = 0; i < n; i++)
    {      
      printf("店舗[%d]の位置 = [%d]\n", i, shop[i]);
    }

  for(i = 1; i < n; i++)
    {
      cent = (shop[i] + shop[i - 1]) / 2;
      range[(i - 1) * 2 + 1] = cent;
      range[i * 2] = cent + 1;
    }
  cent = (d + shop[n - 1]) / 2;
  range[(n - 1) * 2 + 1] = cent;
  range[0] = cent + 1;

  for(i = 0; i < n; i++)
    {
      printf("店舗[%d]の配達範囲: [%d]〜[%d]間\n", i, range[i * 2], range[i * 2 + 1]);
    }

  for(i = 0; i < m; i++)
    {
      scanf("%d", &a);
      for(j = 1; j < n; j++)
	{
	  if((range[j * 2] <= a) && (a <= range[j * 2 + 1]))
	    {
	      printf("配達先[%d]は店舗[%d]から配達します（配達距離[%d])\n", a, j, abs(a - shop[j]));
	      sum += abs(a - shop[j]);
	      break;
	    }
	}
      if((range[0] <= a) && (a < d) || (0 < a) && (a <= range[1]))
	{
	  if((range[(n - 1) * 2 + 1] < a) && (a < d))
	    {
	      sum += d - a;
	      hoge = d - a;
	    }
	  else
	    {
	      sum += a;
	      hoge = a;
	    }
	  printf("配達先[%d]は店舗[0]から配達します（配達距離[%d])\n", a, hoge);
	}
    }
  
  printf("%d\n", sum);

  free(shop);
  free(range);
  return 0;
}