import std;

struct Grid {
    int x;
    int y;
}

void main() {
    int H, W;
    readf("%d %d\n", H, W);

    auto A = new int[][](H, W);
    foreach (i; 0 .. H) {
        A[i] = readln.chomp.split.to!(int[]);
    }

    auto move = [
        Grid(-1, 0),
        Grid(0, 1),
        Grid(1, 0),
        Grid(0, -1)
    ];

    Grid[] que;
    int res;

    foreach (i; 0 .. H) {
        foreach (j; 0 .. W) {
            if (A[i][j] == 0) {
                continue;
            }

            ++res;

            que ~= Grid(i, j);

            while (!que.empty) {
                auto f = que.front;
                que.popFront;

                A[f.x][f.y] = 0;

                foreach (m; move) {
                    auto next = f;
                    next.x += m.x, next.y += m.y;

                    if (next.x < 0 || next.x >= H || next.y < 0 || next.y >= W) {
                        continue;
                    }

                    if (A[next.x][next.y] == 0) {
                        continue;
                    }

                    que ~= next;
                }
            }
        }
    }

    res.writeln;
}