import sys
sys.setrecursionlimit(10**4)
h,w=map(int,input().split())
g=[list(map(int,input().split())) for _ in range(h)]
def dfs(i,j):
    g[i][j]=0
    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:
            dfs(y,x)
ans=0
for i in range(h):
    for j in range(w):
        if g[i][j]==1:
            ans+=1
            dfs(i,j)
print(ans)