h, w = map(int, input().split())
A = [list(map(int, input().split())) for _ in range(h)]
used = [[False] * w for _ in range(h)]
directions = [(0, 1), (1, 0), (0, -1), (-1, 0)]

ans = 0
for i in range(h):
    for j in range(w):
        if used[i][j] or A[i][j] == 0:
            continue
        ans += 1
        stack = [(i, j)]
        while stack:
            ii, jj = stack.pop()
            for di, dj in directions:
                ni = ii + di
                nj = jj + dj
                if ni == -1 or ni == h or nj == -1 or nj == w:
                    continue
                if A[ni][nj] == 0 or used[ni][nj]:
                    continue
                used[ni][nj] = True
                stack.append((ni, nj))
        
print(ans)