class No697:
    height, width = 0, 0
    id = 2

    def __init__(self):
        self.height, self.width = map(int, input().split(" "))
        self.water_map = [[0 for i in range(self.width)] for j in range(self.height)]
        for i in range(self.height):
            self.water_map[i] = list(map(int, input().split(" ")))

    def solve(self):
        search_dic = [(0, 1, 0, -1), (1, 0, -1, 0)]
        for i in range(self.height):
            for j in range(self.width):
                if self.water_map[i][j] == 1:
                    pos_id = self.id
                    for k in range(4):
                        vx = j + search_dic[0][k]
                        vy = i + search_dic[1][k]
                        if 0 <= vx < self.width and 0 <= vy < self.height:
                            if not self.water_map[vy][vx] == 0 and not self.water_map[vy][vx] == 1:
                                pos_id = self.water_map[vy][vx]
                    self.water_map[i][j] = pos_id
                    if pos_id == self.id:
                        self.id += 1

        for i in range(self.height):
            for j in range(self.width):
                my_id = self.water_map[i][j]
                c_id = my_id
                if not my_id == 0:
                    for k in range(4):
                        vx = j + search_dic[0][k]
                        vy = i + search_dic[1][k]
                        if 0 <= vx < self.width and 0 <= vy < self.height:
                            if not self.water_map[vy][vx] == 0 and not self.water_map[vy][vx] == my_id:
                                c_id = self.water_map[vy][vx]
                    self.water_map[i][j] = c_id
        num_set = set()
        for num_list in self.water_map:
            num_set = num_set | set(num_list)
        if num_set.isdisjoint({0}):
            return len(num_set)
        else:
            return len(num_set) - 1


if __name__ == "__main__":
    que = No697()
    ans = que.solve()
    print(ans)