m,n=map(int,input().split()) results1=[] results2=[] for i in range(m): a=list(map(int,input().split())) results1.append(a) for i in range(m): b=list(map(int,input().split())) results2.append(b) res=0 for col in range(m): for row in range(n): if results1[row][col]==results2[row][col]: res+=1 print("{:.2f}".format((100*res)/(n*m)))