n, m = map(int, input().split()) a = [] b = [] for i in range(n): c = list(map(int, input().split())) a.append(c) for i in range(n): c = list(map(int, input().split())) b.append(c) ans = 0 for i in range(n): for j in range(m): if a[i][j] != b[i][j]: ans += 1 print('%.2f' % ((n * m - ans) / (n * m) * 100))