import sys
from collections import deque
sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI2(): return list(map(int,sys.stdin.readline().rstrip()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())
def LS2(): return list(sys.stdin.readline().rstrip())


H,W = MI()
A = [LI() for _ in range(H)]

flag = [[0]*W for _ in range(H)]
directions = [(-1,0),(1,0),(0,-1),(0,1)]
ans = 0
for i in range(H):
    for j in range(W):
        if flag[i][j] == 1 or A[i][j] == 0:
            continue
        ans += 1
        deq = deque([(i,j)])
        flag[i][j] = 1
        while deq:
            x,y = deq.pop()
            for dx,dy in directions:
                nx,ny = x+dx,y+dy
                if 0 <= nx < H and 0 <= ny < W and flag[nx][ny] == 0 and A[nx][ny] == 1:
                    flag[nx][ny] = 1
                    deq.append((nx,ny))

print(ans)