a, b = map(int, input().split()) c, d = [], [] for i in range(a): e = list(map(int, input().split())) c.append(e) for i in range(a): f = list(map(int, input().split())) d.append(f) count, s = 0, a * b for j in range(a): for k in range(b): if c[j][k] == d[j][k]: count += 1 print('%.2f' % (count/s*100))