Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}

func getNextUint64(scanner *bufio.Scanner) uint64 {
	i, _ := strconv.ParseUint(getNextString(scanner), 10, 64)
	return i
}

func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}

func main() {
	fp := os.Stdin
	wfp := os.Stdout
	cnt := 0

	if os.Getenv("MASPY") == "ますピ" {
		fp, _ = os.Open(os.Getenv("BEET_THE_HARMONY_OF_PERFECT"))
		cnt = 0
	}
	if os.Getenv("MASPYPY") == "ますピッピ" {
		wfp, _ = os.Create(os.Getenv("NGTKANA_IS_GENIUS10"))
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(wfp)
	for solve(scanner, writer) {

	}
	for i := 0; i < cnt; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
	writer.Flush()
}

func solve(scanner *bufio.Scanner, writer *bufio.Writer) bool {
	sol := solver{}
	sol.w = getNextInt(scanner)
	sol.h = getNextInt(scanner)
	if sol.w == 0 && sol.h == 0 {
		return false
	}
	sol.land = makeInts(sol.h, sol.w)
	for y := 0; y < sol.h; y++ {
		for x := 0; x < sol.w; x++ {
			sol.land[y][x] = getNextInt(scanner)
		}
	}
	ans := 0
	for y := 0; y < sol.h; y++ {
		for x := 0; x < sol.w; x++ {
			if sol.land[y][x] == 0 {
				continue
			}
			ans++
			sol.dfs(y, x)
		}
	}
	fmt.Fprintln(writer, ans)
	return true
}

type solver struct {
	w, h int
	land [][]int
}

func (sol *solver) dfs(y, x int) {
	if y < 0 {
		return
	}
	if y >= sol.h {
		return
	}
	if x < 0 {
		return
	}
	if x >= sol.w {
		return
	}
	if sol.land[y][x] == 0 {
		return
	}
	sol.land[y][x] = 0
	dy := [8]int{-1, -1, -1, 0, 0, 1, 1, 1}
	dx := [8]int{-1, 0, 1, -1, 1, -1, 0, 1}
	for i := 0; i < 8; i++ {
		sol.dfs(y+dy[i], x+dx[i])
	}
}
func makeInts(h, w int) [][]int {
	index := make([][]int, h, h)
	data := make([]int, h*w, h*w)
	for i := 0; i < h; i++ {
		index[i] = data[i*w : (i+1)*w]
	}
	return index
}

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

static const int MAX_H = 50;
static const int MAX_W = 50;

int H, W;
char grid[MAX_H][MAX_W + 1];
bool reached[MAX_H][MAX_W];

#define OCTAS
#ifdef OCTAS
static const int dh[]{-1, -1, -1, 0, 0, +1, +1, +1};
static const int dw[]{-1, 0, +1, -1, +1, -1, 0, +1};
#else
static const int dh[]{-1, 0, 0, +1};
static const int dw[]{0, -1, +1, 0};
#endif

bool dfs(int h, int w) {
  reached[h][w] = true;

  for (int i{}; i < sizeof(dh) / sizeof(int); ++i) {
    int nh = h + dh[i];
    if (nh < 0 || nh >= H)
      continue;
    int nw = w + dw[i];
    if (nw < 0 || nw >= W)
      continue;
    if (grid[nh][nw] == '0' || reached[nh][nw])
      continue;
    if (dfs(nh, nw))
      return true;
  }

  return false;
}

int main() {
  while (true) {
    cin >> W >> H;
    if (W == 0 && H == 0) break;
    for (int h{}; h < H; ++h) {
      for (int w{}; w < W; ++w) {
        cin >> grid[h][w];
      }
    }
    fill_n(reached[0], MAX_H * MAX_W, false);
    int count{};
    for (int h{}; h < H; ++h) {
      for (int w{}; w < W; ++w) {
        if (grid[h][w] == '0' || reached[h][w])
          continue;
        dfs(h, w);
        ++count;
      }
    }
    cout << count << endl;
  }
}

C++: // C++ 14
#include <iostream>
#include <string>
#include <vector>
#include <list>
#include <algorithm>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <unordered_map>
#include <math.h>

#define ll long long
#define Int ll
#define loop(__x, __start, __end) for(Int __x = __start; __x < __end; __x++)
#define loopdown(__x, __start, __end) for(Int __x = __start; __x > __end; __x--)
#define rep(__n) for(Int __x = 0; __x < __n; __x++)
#define span(__a,__x,__y) __a.begin()+__x,__a.begin()+__y
#define span_all(__a) __a.begin(),__a.end()
#define len(__x) (__x.size())
#define last(__x) (__x[__x.size()-1])

using namespace std;

struct Point {
  Int x, y;
  Point(Int x, Int y): x(x), y(y) {}
  Point(): x(0), y(0) {}

  bool operator< (const Point &p1) const {
    return x < p1.x && y < p1.y;
  }
};
ostream & operator << (ostream & out, Point const & v) {
  out << "Point(" << v.x << ", " << v.y << ')';
  return out;
}

istream & operator >> (istream & in, Point & v) {
  Int x, y;
  in >> x; in >> y; v.x = x; v.y = y;
  return in;
}

// Geometry

#define EPS 0.0000000001

class Vector2 {
public:
  double x, y;
  
  Vector2(double x = 0, double y = 0): x(x), y(y) {}
  
  Vector2 operator + (Vector2 v) { return Vector2(x + v.x, y + v.y); }
  Vector2 operator - (Vector2 v) { return Vector2(x - v.x, y - v.y); }
  Vector2 operator * (double k) { return Vector2(x * k, y * k); }
  Vector2 operator / (double k) { return Vector2(x / k, y / k); }
  
  double length() { return sqrt(norm()); }
  double norm() { return x * x + y * y; }
  double dot (Vector2 v) { return x * v.x + y * v.y; }
  double cross (Vector2 v) { return x * v.y - y * v.x; }
  
  bool operator < (const Vector2 &v) const {
    return x != v.x ? x < v.x : y < v.y;
  }
  
  bool operator == (const Vector2 &v) const {
    return fabs(x - v.x) < EPS && fabs(y - v.y) < EPS;
  }
};

ostream & operator << (ostream & out, Vector2 const & v) { 
  out<< "Vector2(" << v.x << ", " << v.y << ')';
  return out;
}

istream & operator >> (istream & in, Vector2 & v) { 
  double x, y;
  in >> x;
  in >> y;
  v.x = x;
  v.y = y;
  return in;
}

void solve();

Int W, H;
vector<vector<bool> > M(51, vector<bool>(51, false));

void input() {
  while (true) {
    cin >> W >> H;
    if (W == 0 && H == 0) return;
    bool b;
    loop(h,0,H) {
      loop(w,0,W) {
        cin >> b;
        if (b) M.at(w).at(h) = true;
      }
    }
    solve();
  }
}

void dfs(Int h, Int w) {
  M.at(w).at(h) = false;
  for (int x=-1; x<=1; x++) {
    for (int y=-1; y<=1; y++) {
      if (x == 0 && y == 0) continue;
      Int x1 = w + x, y1 = h + y;
      if (x1 < 0 || W <= x1) continue;
      if (y1 < 0 || H <= y1) continue;
      if (!M.at(x1).at(y1)) continue;
      dfs(y1, x1);
    }
  }
}

void solve() {
  Int count = 0;
  loop(h,0,H) {
    loop(w,0,W) {
      bool b = M.at(w).at(h);
      if (b) {
        count++;
        dfs(h, w);
      }
    }
  }
  cout << count << endl;
}

int main() {
  input();
  return 0;
}

C++: #include<cstdio>
#include<cstdlib>
#include<iostream>
#include<algorithm>
#include<vector>
#include<stack>
#include<queue>
#include<string>
#include<cmath>
#include<cstdint>
#include<cassert>
using namespace std;

typedef int64_t i64;typedef int32_t i32;
typedef int16_t i16;typedef int8_t i8;
typedef uint64_t ui64;typedef uint32_t ui32;
typedef uint16_t ui16;typedef uint8_t ui8;

typedef i32 int__;
#define rep(i,j) for(int__ i=0;i<j;i++)
#define repeat(i,j,k) for(int__ i=(j);i<(k);i++)
#define repeat_eq(i,j,k) for(int__ i=(j);i<=(k);i++)
#define all(v) begin(v),end(v)

const i32 INF=1<<30;//=10E10

vector< vector<i32> > M;
i32 w,h;

void dfs(int y,int x,int id){
  int dx[]={1,0,-1,0,1,-1,1,-1};
  int dy[]={0,1,0,-1,1,1,-1,-1};
  M[y][x]=id;
  rep(i,8){
      int nx=x+dx[i];
      int ny=y+dy[i];
      if(0<=nx && nx<w and 0<=ny && ny<h){
	if(M[ny][nx]==1)dfs(ny,nx,id);
      }
  }
}

int main()
{
  while(true){
  
    cin>>w>>h;
    if(!w and !h)break;
    M.clear();
    M.resize(h,vector<i32>(w));
    rep(i,h){
      rep(j,w){
	cin>>M[i][j];
      }
    }
    
    int ans=0;
    rep(i,h)rep(j,w){
      if(M[i][j]==1){
	dfs(i,j,ans++ +2);
      }
    }
    
    cout<<ans<<endl;
  }
  
  return 0;
}