from collections import deque

H, W = map(int, input().split())
m = []
for i in range(H):
    m.append(list(map(int, input().split())))

xx = [1, 0, -1, 0]
yy = [0, 1, 0, -1]

q = deque()
cnt = 0
seen = [[False]*W for _ in range(H)]
for i in range(H):
    for j in range(W):
        if seen[i][j] == False and m[i][j] == 1:
            seen[i][j] = True
            q.append((i, j))
            cnt += 1
            while q:
                x, y = q.popleft()
                for px, py in zip(xx, yy):
                    cx = x+px
                    cy = y+py
                    if 0<=cx<H and 0<=cy<W and m[cx][cy] == 1 and seen[cx][cy] == False:
                        q.append((cx, cy))
                        seen[cx][cy] = True
        else:
            seen[i][j] = True
print(cnt)