from collections import deque
H, W = map(int,input().split())
L = [list(map(int,input().split())) for _ in range(H)]
def bfs(i, j):
    L[i][j] = 0
    Q = deque()
    Q.append((i, j))
    while Q:
        i, j = Q.popleft()
        dy = [0, 1, 0, -1]
        dx = [1, 0, -1, 0]
        for k in range(4):
            y = i + dy[k]
            x = j + dx[k]
            if not(0 <= y < H and 0 <= x < W):
                continue
            if L[y][x] == 1:
                L[y][x] = 0
                Q.append((y, x))
ans = 0
for i in range(H):
    for j in range(W):
        if L[i][j] == 1:
            ans += 1
            bfs(i, j)
print(ans)