import sys
sys.setrecursionlimit(100000)
h,w=map(int,input().split())
g=[list(map(int,input().split())) for _ in range(h)]
def dfs(y,x):
    g[y][x]=0
    dy=[0,1,0,-1]
    dx=[1,0,-1,0]
    for i in range(4):
        ny=y+dy[i];nx=x+dx[i]
        if 0<=ny<h and 0<=nx<w and g[ny][nx]==1:
            dfs(ny,nx)
    return 
ans=0
for i in range(h):
    for j in range(w):
        if g[i][j]==1:
            ans+=1
            dfs(i,j)
print(ans)