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 main() {
    let (H, W) = readInt2()
    var A = readLines(H)
    let dirc = [(-1, 0),(0, 1),(1, 0),(0, -1)]
    var ans = 0
    for i in 0..<H {
        for j in 0..<W {
            if !A[i][j] {
                continue
            }
            ans += 1
            var frontier: [(Int, Int)] = []
            frontier.append((i, j))
            while !frontier.isEmpty {
                let (h, w) = frontier.popLast()!
                A[h][w] = false
                for (y, x) in dirc {
                    let sucY = h+y
                    let sucX = w+x
                    if sucY < 0 || sucY >= H || sucX < 0 || sucX >= W || !A[sucY][sucX] {
                        continue
                    }
                    frontier.append((sucY, sucX))
                }
                
            }
        }
    }
    print(ans)
}

main()