from array import array
from collections import deque

H, W = map(int, input().split())
A = [array('I', map(int, input().split())) for _ in range(H)]
pair2int = lambda h, w: h * W + w
int2pair = lambda i: divmod(i, W)
nonvisited = array('I', [1] * (H * W))
ans = 0
for i in range(H * W):
    h, w = int2pair(i)
    if A[h][w] and nonvisited[i]:
        ans += 1
        # bfs
        d = deque([i])
        while d:
            x = d.popleft()
            h, w = int2pair(x)
            nonvisited[x] = 0
            for dh, dw in ((0, 1), (1, 0), (0, -1), (-1, 0)):
                hdh, wdw = h + dh, w + dw
                if 0 <= hdh < H and 0 <= wdw < W and A[hdh][wdw] and nonvisited[pair2int(hdh, wdw)]:
                    d.append(pair2int(hdh, wdw))
print(ans)