func readInt2() -> (Int, Int) {
    let l = readLine()!.split(separator: " ").map{Int($0)!}
    return (l[0], l[1])
}

func readLines(_ n: Int) -> [[Bool]] {
    return (0..<n).map{(Int) -> [Bool] in
        return readLine()!.split(separator: " ").map{$0 == "1"}
    }
}

func dfs(_ i: Int, _ j: Int, _ grid: inout [[Bool]], _ H: Int, _ W: Int) -> Int{
    var frontier: [(Int, Int)] = []
    frontier.append((i, j))
    while !frontier.isEmpty {
        let (h, w) = frontier.popLast()!
        grid[h][w] = false
        for (y, x) in [(-1, 0),(0, 1),(1, 0),(0, -1)] {
            let sucY = h+y
            let sucX = w+x
            if sucY < 0 || sucY >= H || sucX < 0 || sucX >= W || !grid[sucY][sucX] {
                continue
            }
            frontier.append((sucY, sucX))
        }
    }
    return 1
}

func main() {
    let (H, W) = readInt2()
    var A = readLines(H)
    var ans = 0
    for i in 0..<H {
        for j in 0..<W {
            if !A[i][j] {
                continue
            }
            ans += dfs(i, j, &A, H, W)
        }
    }
    print(ans)
}

main()