from collections import deque

H, W = map(int, input().split())
pond = []

for i in range(H):
    a = [int(i) for i in input().split()]
    pond.append(a)

ans = 0
q = deque()
toward = [[0, 1], [0, -1], [1, 0], [-1, 0]]
visited = [([False] * W) for i in range(H)]


def search():
    while len(q) > 0:
        x, y = q.popleft()
        visited[x][y] = True
        for k in range(4):
            dx, dy = x + toward[k][0], y + toward[k][1]
            if (0 <= dx < H) and (0 <= dy < W):
                if (pond[dx][dy] == 1) and (visited[dx][dy] == False):
                    visited[dx][dy] = True
                    q.append([dx, dy])


for i in range(H):
    for j in range(W):
        if (pond[i][j] == 1) and (visited[i][j] == False):
            q.append([i, j])
            search()
            ans += 1

print(ans)