h,w = input().split()
h,w = int(h),int(w)

lst = []
cnt = 0

def tansaku(x,y):
    if lst[x][y]=="0":
        return
    lst[x][y]="0"
    tansaku(x+1,y)
    tansaku(x-1,y)
    tansaku(x,y+1)
    tansaku(x,y-1)

for a in range(h):
    lst.append(["0"]+input().split()+["0"])
lst.insert(0,["0"]*(w+2))
lst.append(["0"]*(w+2))

for a in range(1,h+1):
    for b in range(1,w+1):
        if lst[a][b]=="1":
            cnt+=1
            tansaku(a,b)

print(cnt)