func readInt2() -> (Int16, Int16) {
    let l = readLine()!.split(separator: " ").map{Int16($0)!}
    return (l[0], l[1])
}

func readLines(_ n: Int16) -> [[Bool]] {
    return (0..<n).map{(Int16) -> [Bool] in
        return readLine()!.split(separator: " ").map{$0 == "1"}
    }
}

func dfs(_ i: Int16, _ j: Int16, _ grid: inout [[Bool]], _ H: Int16, _ W: Int16) -> Int{
    var frontier: [(Int16, Int16)] = []
    frontier.append((i, j))
    let dires: [(Int16, Int16)] = [(-1, 0),(0, 1),(1, 0),(0, -1)]
    while !frontier.isEmpty {
        let (h, w) = frontier.popLast()!
        grid[Int(h)][Int(w)] = false
        for (y, x) in dires {
            let sucY = h+y
            let sucX = w+x
            if sucY < 0 || sucY >= H || sucX < 0 || sucX >= W || !grid[Int(sucY)][Int(sucX)] {
                continue
            }
            frontier.append((sucY, sucX))
        }
    }
    return 1
}

func main() {
    let (H, W): (Int16, Int16) = readInt2()
    var A = readLines(H)
    var ans = 0
    for i in 0..<H {
        for j in 0..<W {
            if !A[Int(i)][Int(j)] {
                continue
            }
            ans += dfs(i, j, &A, H, W)
        }
    }
    print(ans)
}

main()