H,W = map(int,input().split())
A = [list(map(int,input().split())) for _ in range(H)]

count = 0
stack = []
for h in range(H):
    for w in range(W):
        if A[h][w] == 1:
            count += 1
            stack.append((h,w))
            A[h][w] = 0
            while stack:
                x,y = stack.pop()
                for i,j in [(0,1),(0,-1),(1,0),(-1,0)]:
                    if 0 <= x + i < H and 0 <= y + j < W:
                        if A[x+i][y+j]:
                            A[x+i][y+j] = 0
                            stack.append((x+i,y+j))
print(count)