from collections import deque

def bfs(sx, sy):
    S[sx][sy] = 0
    queue = deque([])
    queue.append((sx, sy))
    
    while len(queue) > 0:
        cx, cy = queue.popleft()
        
        for dx, dy in [(-1, 0), (1, 0), (0, -1), (0, 1)]:
            nx, ny = cx + dx, cy + dy
            if 0 <= nx < H and 0 <= ny < W:
                if S[nx][ny] == 1:
                    S[nx][ny] = 0
                    queue.append((nx, ny))
    
H, W = map(int, input().split())
S = [list(map(int, input().split())) for _ in range(H)]
ans = 0

for i in range(H):
    for j in range(W):
        if S[i][j] == 1:
            bfs(i, j)
            ans += 1

print(ans)