#!/usr/bin/env python3


import statistics


def compute_min_sum_delta(n, ys):
    m = statistics.median(ys)
    return round(sum(abs(y - m) for y in ys))


def main():
    n = int(input())
    ys = [int(y) for y in input().split()]
    print(compute_min_sum_delta(n, ys))


if __name__ == '__main__':
    main()