def bfs(x,y):
    que=[[x,y]]
    step=[[1,0],[-1,0],[0,1],[0,-1]]
    while que!=[]:
        p=que.pop(0)
        a[p[0]][p[1]]=0
        for i in step:
            nx=p[0]+i[0];ny=p[1]+i[1]
            if 0<=nx<n and 0<=ny<m and a[nx][ny]==1:
                que.append([nx,ny])
        

n,m=map(int,input().split())
a=[]
for i in range(n):
    a.append(list(map(int,input().split())))  
#print(a)
ans=0
for i in range(n):
    for j in range(m):
        if a[i][j]==1:
            ans+=1
            bfs(i,j)
#            print(ans,a)
print(ans)