from collections import deque
h,w=map(int,input().split())
g=[list(map(int,input().split())) for _ in range(h)]
def bfs(i,j):
    g[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 g[y][x]==1:
                g[y][x]=0
                q.append((y,x))
ans=0
for i in range(h):
    for j in range(w):
        if g[i][j]==1:
            ans+=1
            bfs(i,j)
print(ans)