def main():
    n = int(input())
    c = list(map(int,input().split()))  
    maxc = max(c)
    minc = min(c)

    if minc > 0 and maxc > 0:
        minc = 0
    if minc < 0 and maxc < 0:
        maxc = 0
    print(abs(maxc * 2) + abs(minc * 2)) 

if __name__ == "__main__":
    main()