from array import array
from collections import deque

H, W = map(int, input().split())
A = tuple(array('b', map(int, input().split())) for _ in range(H))
pair2int = lambda h, w: h * W + w
int2pair = lambda i: divmod(i, W)
nonvisited = array('b', [1] * (H * W))
directions = ((0, 1), (1, 0), (0, -1), (-1, 0))
ans = 0
# for i in range(H * W):
#     h, w = int2pair(i)
#     if A[h][w] and nonvisited[i]:
#         ans += 1
#         # dfs
#         d = deque([i])
#         while d:
#             x = d.pop()
#             h, w = int2pair(x)
#             nonvisited[x] = 0
#             for dh, dw in directions:
#                 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)