m,n = input().split() n,m = int(n),int(m) a=[] for x in range(m): t=input().split() a.append(t) b=[] for x in range(m): t=input().split() b.append(t) s=0 for x in range(m): for y in range(n): if a[x][y]==b[x][y]: s+=1 res = s/(m*n)*100 print("{:.2f}".format(res))