from collections import deque
H,W=map(int,input().split())

A=[[0]*(W) for _ in range(H)]
for y in range(H):
    B=list(map(int,input().split()))
    A[y]=B

V=[(-1,0),(1,0),(0,-1),(0,1)]
X=0
for y in range(H):
    for x in range(W):
        if A[y][x]==1:
            X+=1
            Q=deque([(x,y)])

            while Q:
                p,q=Q.popleft()
                A[q][p]=0

                for a,b in V:
                    s=p+a
                    t=q+b
                    if 0<=s<W and 0<=t<H:
                        if A[t][s]==1:
                            Q.append((s,t))

print(X)