import sys import math import bisect from heapq import heapify, heappop, heappush from collections import deque, defaultdict, Counter from functools import lru_cache from itertools import accumulate, combinations, permutations, product sys.setrecursionlimit(1000000) MOD = 10 ** 9 + 7 MOD99 = 998244353 input = lambda: sys.stdin.readline().strip() NI = lambda: int(input()) NMI = lambda: map(int, input().split()) NLI = lambda: list(NMI()) SI = lambda: input() SMI = lambda: input().split() SLI = lambda: list(SMI()) EI = lambda m: [NLI() for _ in range(m)] def main(): B = NI() N = NI() C = sorted([NI() for _ in range(N)]) ans = 10**15 for m in C: tmp = 0 over = 0 less = 0 for c in C: if c >= m: over += c-m else: less += m-c if over >= less: tmp = less + over elif over + B >= less: tmp = over + less else: continue ans = min(ans, tmp) print(ans) if __name__ == "__main__": main()