H,W = map(int,input().split())
A = [list(map(int,input().split())) for _ in range(H)]

memo = [[False] * W for _ in range(H)]
ans = 0
q = []
for h in range(H):
    for w in range(W):
        if A[h][w] and memo[h][w] == False:
            ans += 1
            memo[h][w] = True
            q.append((h,w))
            while len(q):
                x,y = q.pop()
                for i,j in [[-1,0],[1,0],[0,1],[0,-1]]:
                    if 0 <= x + i < H and 0 <= y + j < W:
                        if A[x+i][y+j] and memo[x+i][y+j] == False:
                            memo[x+i][y+j] = True
                            q.append((x+i,y+j))
print(ans)