from collections import deque
H, W = map(int, input().split())
A = [list(map(int, input().split())) for _ in range(H)]
dx = [0, 1, 0, -1]
dy = [-1, 0, 1, 0]
ans = 0
for h in range(H):
    for w in range(W):
        if A[h][w] == 1:
            ans += 1
            que = deque()
            que.append((h, w))
            A[h][w] = 0
            while que:
                y, x = que.popleft()
                for i in range(4):
                    xx = x + dx[i]
                    yy = y + dy[i]
                    if 0 <= xx < W and 0 <= yy < H:
                        if A[yy][xx] == 1:
                            que.append((yy, xx))
                            A[yy][xx] = 0
print(ans)