import Foundation

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"}
    }
}

let (H, W) = readInt2()
var A = readLines(H)
var 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()!
            if !A[h][w]{
                continue
            }
            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)