from array import array from collections import deque H, W = map(int, input().split()) A = [array('I', map(int, input().split())) for _ in range(H)] pair2int = lambda h, w: h * W + w int2pair = lambda i: divmod(i, W) nonvisited = array('I', [1] * (H * W)) ans = 0 for i in range(H * W): h, w = int2pair(i) if A[h][w] and nonvisited[i]: ans += 1 # bfs d = deque([i]) while d: x = d.popleft() h, w = int2pair(x) nonvisited[x] = 0 for dh, dw in ((0, 1), (1, 0), (0, -1), (-1, 0)): hdh, wdw = h + dh, w + dw if 0 <= hdh < H and 0 <= wdw < W and A[hdh][wdw] and nonvisited[pair2int(hdh, wdw)]: d.append(pair2int(hdh, wdw)) print(ans)