from collections import deque

Directions = [(1, 0), (0, 1), (-1, 0), (0, -1)]

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

visited = [[False for _ in range(w)] for _ in range(h)]
for i in range(h):
    for j in range(w):
        if A[i][j] == 0:
            visited[i][j] = True

ans = 0
for i in range(h):
    for j in range(w):
        if not visited[i][j]:
            ans += 1
            Que = deque([(i, j)])
            visited[i][j] = True
            while Que:
                ci, cj = Que.popleft()
                for di, dj in Directions:
                    ni, nj = ci + di, cj + dj
                    if 0 <= ni < h and 0 <= nj < w and not visited[ni][nj]:
                        visited[ni][nj] = True
                        Que.append((ni, nj))
print(ans)