import sys
input = sys.stdin.readline
from collections import deque
H,W = map(int,input().split())
A = [list(map(int,input().split())) for y in range(H)]
ans = 0
#dxy = [(-1,0), (0,-1), (0,1), (1,0)]
dxy = [(0,1), (1,0)]

for i in range(H) :
    for j in range(W) :
        if A[i][j] != 1 :
            continue
        ans += 1
        A[i][j] = 0
        q = deque([(i, j)])
        while q :
            y, x = q.popleft()
            for dy,dx in dxy :
                ny,nx = y+dy, x+dx
                if ny<0 or ny>=H or nx<0 or nx>=W :
                    continue
                if A[ny][nx] != 1 :
                    continue
                q.append((ny, nx))
                A[ny][nx] = 0
print(ans)