w = [] z = [] a,b = map(int,input().split()) for i in range(a+1): s = input().split() s.append(w) for i in range(a+2,2*a+1): d = input().split() d.append(z) e = 0 m = 0 q = 0 l = 0 p = len(w)+len(z) for i in range(p//2): if e == b: l = l+1 elif w[l][q]==z[l][q]: m = m+1 e = e+1 q = q+1 print(m)