Go: package main

import (
	"bufio"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

var (
	readString func() string
	readBytes  func() []byte
	stdout     *bufio.Writer
)

func init() {
	readString, readBytes = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) (func() string, func() []byte) {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), math.MaxInt32)
	r.Split(bufio.ScanWords)

	f1 := func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
	f2 := func() []byte {
		return []byte(f1())
	}
	return f1, f2
}

func readInt() int {
	return int(readInt64())
}

func readInt64() int64 {
	i, err := strconv.ParseInt(readString(), 10, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(readString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

func printf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(stdout, f, args...)
}

func println(args ...interface{}) (int, error) {
	return fmt.Fprintln(stdout, args...)
}

func eprintln(args ...interface{}) (int, error) {
	return fmt.Fprintln(os.Stderr, args...)
}

func eprintf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(os.Stderr, f, args...)
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func min64(a, b int64) int64 {
	if a < b {
		return a
	}
	return b
}

func max(a, b int) int {
	if a < b {
		return b
	}
	return a
}

func max64(a, b int64) int64 {
	if a < b {
		return b
	}
	return a
}

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

func abs64(a int64) int64 {
	if a < 0 {
		return -a
	}
	return a
}

func gcd(a, b int) int {
	if b == 0 {
		return a
	}
	return gcd(b, a%b)
}

func gcd64(a, b int64) int64 {
	if b == 0 {
		return a
	}
	return gcd64(b, a%b)
}

// readString() string
// readInt() int
// readInt64() int64
// readFloat64() float64

// -----------------------------------------------------------------------------

func main() {
	defer stdout.Flush()

	for {
		ans, ok := solve()
		if !ok {
			break
		}
		println(ans)
	}

}

func solve() (int, bool) {
	w := readInt()
	h := readInt()
	if w == 0 && h == 0 {
		return 0, false
	}

	c := make([][]int, h+2)
	c[0] = make([]int, w+2)
	c[h+1] = make([]int, w+2)
	for i := 1; i-1 < h; i++ {
		c[i] = make([]int, w+2)
		for j := 1; j-1 < w; j++ {
			c[i][j] = readInt()
		}
	}

	var ans int
	for i := 1; i-1 < h; i++ {
		for j := 1; j-1 < w; j++ {
			if 0 < c[i][j] {
				ans++
				dfs(c, i, j)
			}
		}
	}
	return ans, true
}

func dfs(c [][]int, y, x int) {
	c[y][x] = 0
	dx := []int{-1, 0, 1, -1, 1, -1, 0, 1}
	dy := []int{-1, -1, -1, 0, 0, 1, 1, 1}
	for i := range dx {
		nx := x + dx[i]
		ny := y + dy[i]
		if 0 < c[ny][nx] {
			dfs(c, ny, nx)
		}
	}
}

// -----------------------------------------------------------------------------

C++: #include<bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int,int> P;

bool ok=true;
int c[60][60];
int w,h;
bool seen[60][60];
int dx[8]={1,-1,0,0,1,-1,1,-1};
int dy[8]={1,-1,1,-1,0,0,-1,1};

void dfs(int v,int u){
	if(!seen[v][u]){
		seen[v][u]=true;
		for(int i=0;i<8;i++){
			if(v+dx[i]>=0&&v+dx[i]<h&&u+dy[i]>=0&&u+dy[i]<w&&c[v+dx[i]][u+dy[i]]==1)dfs(v+dx[i],u+dy[i]);
		}
	}
	return;
}

int main(){
	while(ok){
		cin>>w>>h;
		if(w==0||h==0){
			ok=false;
			return 0;
		}
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				cin>>c[i][j];
			}
		}
		for(int i=0;i<60;i++){
			for(int j=0;j<60;j++)seen[i][j]=false;
		}
		int ans=0;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				if(c[i][j]==1&&!seen[i][j]){
					ans++;
					dfs(i,j);
				}
			}
		}
		cout<<ans<<endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
       
using namespace std;
typedef long long ll;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
       

template <typename T>
class Grid {
  struct Pos {
    int i, j;
    Pos(int i, int j) : i(i), j(j) {}
  };

  int H, W;
  vector<vector<T>> G;

  vector<int> di8 = {1, 1, 0, -1, -1, -1, 0, 1},
              dj8 = {0, 1, 1, 1, 0, -1, -1, -1};
  vector<int> di4 = {1, 0, -1, 0}, dj4 = {0, 1, 0, -1};

  vector<Pos> neighbor(int i, int j, const vector<int>& dis,
                       const vector<int>& djs) const {
    vector<Pos> res;
    for (int k = 0; k < dis.size(); ++k) {
      if (in(i + dis[k], j + djs[k])) res.emplace_back(i + dis[k], j + djs[k]);
    }
    return res;
  }

 public:
  static bool in(int H, int W, int i, int j) {
    return 0 <= i && i < H && 0 <= j && j < W;
  }

  Grid(int H, int W) : H(H), W(W) { G.resize(H, vector<T>(W)); }

  vector<T>& operator[](int i) { return G[i]; }

  bool in(int i, int j) const { return (0 <= i && i < H && 0 <= j && j < W); }

  vector<Pos> neighbor8(int i, int j) const { return neighbor(i, j, di8, dj8); }

  vector<Pos> neighbor4(int i, int j) const { return neighbor(i, j, di4, dj4); }

  void scanFrom(istream& strm) { for (int i = 0; i < (int)(H); ++i) for (int j = 0; j < (int)(W); ++j) strm >> G[i][j]; }

  void outputTo(ostream& strm) {
    for (int i = 0; i < (int)(H); ++i) {
      for (int j = 0; j < (int)(W); ++j) cout << G[i][j];
      strm << endl;
    }
  }
};

template <typename T>
inline istream& operator>>(istream& strm, Grid<T>& g) {
  g.scanFrom(strm);
  return strm;
}

template <typename T>
inline ostream& operator<<(ostream& strm, Grid<T>& g) {
  g.outputTo(strm);
  return strm;
}

int main() {
  int w, h;
  while (true) {
    cin >> w >> h;
    if (w == 0 && h == 0) break;
    Grid<int> grid(h, w);
    cin >> grid;

    function<void(int, int)> dfs = [&](int i, int j) {
      grid[i][j] = 0;
      for (auto& p : grid.neighbor8(i, j)) {
        if (grid[p.i][p.j]) dfs(p.i, p.j);
      };
    };

    int ans = 0;
    for (int i = 0; i < (int)(h); ++i) for (int j = 0; j < (int)(w); ++j) {
      if (grid[i][j]) {
        dfs(i, j);
        ++ans;
      }
    }
    cout << ans << endl;
  }

  return 0;
}

C++: #include <cstdio>
#include <cstdint>
#include <vector>
#include <algorithm>
#include <utility>
#include <set>

class union_find {
  mutable std::vector<intmax_t> c;

public:
  union_find(size_t n): c(n, -1) {}

  size_t find(size_t v) const {
    if (c[v] < 0) return v;
    return (c[v] = find(c[v]));
  }

  bool unite(size_t u, size_t v) {
    u = find(u);
    v = find(v);
    if (u == v) return false;
    if (-c[u] > -c[v]) std::swap(u, v);
    c[v] += c[u];
    c[u] = v;
    return true;
  }

  bool connected(size_t u, size_t v) const { return (find(u) == find(v)); }

  size_t size() const { return c.size(); }
  size_t size(size_t v) const {
    return -c[find(v)];
  }
};

constexpr size_t m1 = -1;
constexpr size_t di[] = {m1, m1, m1, 0, 0, 1, 1, 1};
constexpr size_t dj[] = {m1, 0, 1, m1, 1, m1, 0, 1};

int testcase_ends() {
  size_t h, w;
  scanf("%zu %zu", &w, &h);
  if (h == 0 && w == 0) return 1;

  std::vector<std::vector<int>> c(h, std::vector<int>(w));
  for (auto& ci: c)
    for (auto& cij: ci) scanf("%d", &cij);

  union_find uf(h*w);
  for (size_t i = 0; i < h; ++i)
    for (size_t j = 0; j < w; ++j) {
      if (c[i][j] == 0) continue;
      for (size_t k = 0; k < 8; ++k) {
        size_t ni = i + di[k];
        size_t nj = j + dj[k];
        if (!(ni < h && nj < w)) continue;
        if (c[ni][nj] == 0) continue;
        uf.unite(i*w+j, ni*w+nj);
      }
    }

  std::set<size_t> r;
  for (size_t i = 0; i < h; ++i)
    for (size_t j = 0; j < w; ++j)
      if (c[i][j] == 1)
        r.insert(uf.find(i*w+j));

  printf("%zu\n", r.size());
  return 0;
}

int main() {
  while (!testcase_ends()) {}
}