#include <stdio.h>
#include <iostream>
#include <math.h>

void quick_sort(long long int *data, int left, int right)
{
  int i = left;  
  int j = right;
  int pivot = data[(left+right)/2];

  while(1) {
    while (data[i] < pivot) {
      i++;
    }

    while (pivot < data[j]) {
      j--;
    }

    if (i >= j) {
      break;
    }

    long long int tmp = data[i];
    data[i] = data[j];
    data[j] = tmp;

    i++;
    j--;
  }

  if (left < i-1) {
    quick_sort(data, left, i-1);
  }
  if (j+1 < right) {
    quick_sort(data, j+1, right);
  }
}

void showdata(long long int *data, int num)
{
  for(int i=0; i<num; i++) {
    printf("%lld\n", data[i]);
  }
}

long long int move_point(long long int *data, int num)
{
  long long int target = data[(num-1)/2];
  long long int sum = 0;

  for(int i=0; i<num; i++) {
    sum += abs(data[i] - target);
  }

  return sum;
}

int main(void)
{
  int num;
  scanf("%d", &num);
  
  long long int *data;
  data = new long long int[num];
  //data = (long long int *)malloc(num * sizeof(long long int));
  for(int i=0; i<num; i++){
    scanf("%lld", &data[i]);
    //printf("%lld\n", data[i]);
  }

  quick_sort(data, 0, num-1);
//showdata(data, num);

  long long int sum = move_point(data, num);
  printf("%lld\n", sum);
  
  return 0;
}