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

int main(void)
{
  char *road;
  int d, n, m;
  int min, tmp, sum;
  int i, j, a;

  scanf("%d%d%d", &d, &n, &m);
  road = (char *)malloc(sizeof(char) * d);
  memset(road, 0, sizeof(char) * d);

  for(i = 0; i < n - 1; i++)
    {
      scanf("%d", &a);
      road[a] = 1;
    }
  road[0] = 1;

  for(i = 0; i < d; i++)
    {
      printf("[%d] : %d\n", i, road[i]);
    }

  sum = 0;
  for(i = 0; i < m; i++)
    {
      scanf("%d", &a);
      min = d;
      for(j = a; ; j++)
	{
	  if(j == d) j = 0;
	  if(road[j] == 1)
	    {
	      tmp = j - a;
	      if(tmp < 0)
		{
		  tmp += d;
		}
	      if(tmp < min) min = tmp;
	      printf("時計回り: [%d]\n", j);
	      break;
	    }
	}
      for(j = a; ; j--)
	{
	  if(j < 0) j = d - 1;
	  if(road[j] == 1)
	    {
	      tmp = a - j;
	      if(tmp < 0)
		{
		  tmp += d;
		}
	      if(tmp < min) min = tmp;
	      printf("反時計回り: [%d]\n", j);
	      break;
	    }
	}
      sum += min;
      printf("sum = %d\n", sum);
    }

  printf("%d\n", sum);
  
  return 0;
}