10137.py

#!/usr/bin/env python3
# https://uva.onlinejudge.org/external/101/10137.pdf
import math
while True:
    n=int(input())
    if n==0:break
    values=[float(input())for _ in range(n)]
    s=sum(values)
    t1=math.ceil(100*s/n)/100
    t2=int(100*s/n)/100
    z1=0
    z2=0
    for v in values:
        if v>=t1:z1+=v-t1
        else:z2+=t2-v
    print('${:.2f}'.format(max(z1,z2)))