from collections import deque
from itertools import combinations, product


def main():
    H, W = map(int, input().split())
    field_map = tuple(tuple(map(int, input().split())) for _ in range(H))
    searched = [[0]*W for _ in range(H)]

    pond_ctr = 0

    for height_idx, width_idx in product(range(H), range(W)):
        if field_map[height_idx][width_idx] == 0:
            continue
        if searched[height_idx][width_idx] == 1:
            continue

        pond_ctr += 1
        searching = deque(((height_idx, width_idx),))
        searched[height_idx][width_idx] = 1
        while searching:
            current_h_idx, current_w_idx = searching.popleft()
            if field_map[current_h_idx][current_w_idx] == 0:
                continue

            if current_h_idx < H-1 and searched[current_h_idx+1][current_w_idx] == 0:
                searching.append((current_h_idx+1, current_w_idx))
                searched[current_h_idx+1][current_w_idx] = 1

            if current_h_idx > 0 and searched[current_h_idx-1][current_w_idx] == 0:
                searching.append((current_h_idx-1, current_w_idx))
                searched[current_h_idx-1][current_w_idx] = 1

            if current_w_idx < W-1 and searched[current_h_idx][current_w_idx+1] == 0:
                searching.append((current_h_idx, current_w_idx+1))
                searched[current_h_idx][current_w_idx+1] = 1

            if current_w_idx > 0 and searched[current_h_idx][current_w_idx-1] == 0:
                searching.append((current_h_idx, current_w_idx-1))
                searched[current_h_idx][current_w_idx-1] = 1

    print(pond_ctr)


if __name__ == "__main__":
    main()