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

ans = 0
for i in range(h):
    for j in range(w):
        if A[i * w + j] == 0:
            continue
        A[i * w + j] = 0
        ans += 1
        stack = [(i * w + j)]
        while stack:
            tmp = stack.pop()
            ii = tmp // w
            jj = tmp - ii * w
            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 * w + nj] == 0:
                    continue
                A[ni * w + nj] = 0
                stack.append(ni * w + nj)
        
print(ans)