from collections import deque

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

sensor = []
for j in range(h):
    for i in range(w):
        if grid[j][i] == '1':
            sensor.append((i, j))

visited = set()
count = 0

while sensor:
    q = deque()
    q.append(sensor[0])
    sensor.pop(0)
    
    while q:
        x, y = q.popleft()
        
        if (x, y) in visited:
           continue
        
        visited.add((x, y))
        
        for dx, dy in [(0, 1), (0, -1), (1, 0), (-1, 0)]:
            nx, ny = x + dx, y + dy
            if 0 <= nx < w and 0 <= ny < h:
               if grid[ny][nx] == '1' and (nx,ny) not in visited:
                  q.append((nx, ny))

    count += 1
print(count)