import itertools
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)]

visited = set()
ans = 0
for h, w in itertools.product(range(H), range(W)):
    if A[h][w] and (h, w) not in visited:
        ans += 1
        # dfs
        d = deque([(h, w)])
        while d:
            h, w = d.pop()
            visited.add((h, w))
            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 (hdh, wdw) not in visited:
                    d.append((hdh, wdw))
print(ans)