# -*- coding: utf-8 -*-
"""Untitled0.ipynb

Automatically generated by Colab.

Original file is located at
    https://colab.research.google.com/drive/1mvrbrsl2ke_3Bs805onX5zCNTm69EEYX
"""





import math as mt
NC=int(input())                         # No of cities
Ns=int(input())                         # No of different species
Ta=list(map(int,input().split()))       # Total no of individual species in a state
for i in range(NC):
    a1=list(map(int,input().split()))   # No of individual species in a city
    N1=sum(a1)
    DEV1=0
    for j in range(Ns):
        m=((1/Ns)-(a1[j]/N1))**2
        DEV1=DEV1+mt.sqrt(m)
    DEV1=DEV1/Ns
    EVN1=(1-DEV1)
    CN1=0
    for j in range(Ns):
        CN1=CN1+((a1[j]/Ta[j])*EVN1)
    BD=CN1/Ns
    print(BD)