Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	resolve()
}

func resolve() {
	results := []int{}
	for true {
		w, h := scanInt(sc), scanInt(sc)
		if w == 0 && h == 0 {
			break
		}
		grid := make([][]int, h)
		for i := 0; i < h; i++ {
			grid[i] = make([]int, w)
			for j := 0; j < w; j++ {
				grid[i][j] = scanInt(sc)
			}
		}
		num := 0
		for i := range loop0(h) {
			for j := range loop0(w) {
				start := pos{y: i, x: j}
				if grid[start.y][start.x] == 0 {
					continue
				}
				num++
				_dfs(grid, w, h, start)
			}
		}
		results = append(results, num)
	}
	for _, v := range results {
		fmt.Println(v)
	}
	return
}

func _dfs(grid [][]int, w, h int, start pos) {
	grid[start.y][start.x] = 0
	for _, df := range []pos{
		pos{1, 0}, pos{-1, 0},
		pos{0, -1}, pos{0, 1},
		pos{1, 1}, pos{-1, -1},
		pos{-1, 1}, pos{1, -1},
	} {
		np := addPos(start, df)
		if np.y < 0 || h <= np.y || np.x < 0 || w <= np.x {
			continue
		}
		if grid[np.y][np.x] == 0 {
			continue
		}
		_dfs(grid, w, h, np)
	}
}

type pos struct{ x, y int }

func addPos(p, d pos) pos {
	return pos{
		x: p.x + d.x,
		y: p.y + d.y,
	}
}

func loop0(n int) chan int {
	return loop(0, n-1, 1)
}

func loop1(n int) chan int {
	return loop(1, n, 1)
}

func loop(s, e, d int) chan int {
	ch := make(chan int)
	go func() {
		for i := s; i <= e; i += d {
			ch <- i
		}
		close(ch)
	}()
	return ch
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

C++: #include <bits/stdc++.h>

using namespace std;

int c[64][64];

void paint(int y, int x) {
  if (y < 0 || y >= 50 || x < 0 || x >= 50) return;
  if (c[y][x] == 0) return;
  c[y][x] = 0;
  for (int dy = -1; dy <= 1; ++dy) {
    for (int dx = -1; dx <= 1; ++dx) {
      paint(y + dy, x + dx);
    }
  }
}

int main() {
  int H, W;
  while (cin >> W >> H, H) {
    for (int i = 0; i < H; ++i) {
      for (int j = 0; j < W; ++j) {
        cin >> c[i][j];
      }
    }
    int res = 0;
    for (int y = 0; y < H; ++y) {
      for (int x = 0; x < W; ++x) {
        if (c[y][x] == 1) {
          ++res;
          paint(y, x);
        }
      }
    }
    cout << res << endl;
  }
  return 0;
}

C++: #include <iostream>
#include <algorithm>

using namespace std;

int w, h;
int field[51][51];
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};

void dfs(int x, int y)
{
    field[y][x] = -1;

    for (int i = 0; i < 4; i++)
    {
        int nx = x + dx[i];
        int ny = y + dy[i];

        if (nx < 0 || ny < 0 || nx >= w || ny >= h)
            continue;

        if (field[ny][nx] == 1)
            dfs(nx, ny);
    }
}

int main()
{
    while (cin >> w >> h, w || h)
    {
        for (int y = 0; y < h; y++)
        {
            for (int x = 0; x < w; x++)
            {
                cin >> field[y][x];
            }
        }

        int ans = 0;

        for (int y = 0; y < h; y++)
        {
            for (int x = 0; x < w; x++)
            {
                if (field[y][x] == 1)
                {
                    dfs(x, y);
                    ans++;
                }
            }
        }

        cout << ans << endl;
    }

    return 0;
}

C++: #include "bits/stdc++.h"
#include<unordered_map>
#include<unordered_set>
#pragma warning(disable:4996)
using namespace std;
using ld = long double;
template<class T>
using Table = vector<vector<T>>;

//
int dx8[8] = { -1,-1,-1, 0, 1, 1, 1, 0 };
int dy8[8] = { -1, 0, 1, 1, 1, 0,-1,-1 };
//6:28
vector<vector<int>>as;
void check(int y, int x) {
	for (int i = 0; i < 8; ++i) {
		int nx = x + dx8[i];
		int ny = y + dy8[i];
		if (as[ny][nx]) {
			as[ny][nx] = 0;
			check(ny, nx);
		}
	}
}
int main() {
	while (1) {
		as.clear();
		int w, h; cin >> w >> h;
		if (!w)break;
		as.resize(h+2);
		for (int i = 0; i <= h+1; ++i) {
			as[i].emplace_back(0);
			if (i != 0 && i != h + 1) {
				for (int j = 0; j < w; ++j) {
					int c; cin >> c;
					as[i ].emplace_back(c);
				}
			}
			else {
				for (int j = 0; j < w; ++j) {
					as[i].emplace_back(0);
				}
			}
			
			as[i].emplace_back(0);
		}
		int ans = 0;
		for (int i = 1; i <= h; ++i) {
			for (int j = 1; j <= w; ++j) {
				if (as[i][j]) {
					ans++;
					check(i, j);
				}
			}
		}
		cout << ans << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <list>
#include <set>
#include <string>
#include <cmath>
#include <algorithm>
#include <map>

using namespace std;
using ll=long long;
using vi=vector<int>;
using vll=vector<ll>;
using pii=pair<int,int>;
using vs=vector<string>;
using vvi=vector<vi>;
using vpii=vector<pii>;
using si=set<int>;

#define REP(i,a) for(int i=0;i<a;i++)
#define FOR(i,a,b) for(int i=a;i<b;i++)
#define rREP(i,a) for(int i=(a)-1;i>=0;i--)
#define rFOR(i,a,b) for(int i=(a)-1;i>=(b);i--)
#define out(S) cout<<(S)<<endl;
#define beginend(v) (v).begin(),(v).end()
#define IfOut(condition,text) if(condition){out(text);return 0;}
#define IfOutElse(condition,if_text,else_text) if(condition){out(if_text);return 0;}else{out(else_text);return 0;}
#define mod(s) ((s)%(ll)(1e9+7))
ll modpow(ll i, ll j) { ll tmp = 1; while (j) { if (j % 2)tmp = mod(tmp*i); i = mod(i*i); j /= 2; }return tmp; }
#define divmod(a,b) (mod(a*modpow((ll)b,(ll)(1e9+5))))
#define pb(i) push_back(i)
#define fst first
#define snd second
#define Foreach(item,collection) for(auto item:collection)
#define INF (int)1e10
#define removeAll(vec,deleg) auto itr=remove_if(beginend(vec),deleg);vec.erase(itr,vec.end());
void removeAt(string& s, int index) { s.erase(index, 1); }
template<typename T> void removeAt(vector<T>& v, int index) { v.erase(v.begin() + index); }
ll manhattanDistance(ll x1, ll y1, ll x2, ll y2) { return (abs(x2 - x1) + abs(y2 - y1)); }
vector<ll> sieveOfEratosthenes(int max) {ll prime;double sqrtmax = sqrt(max);vector<ll> primeVec, searchVec;FOR(i, 2, max + 1) searchVec.push_back(i);do{prime = searchVec[0];primeVec.push_back(prime);auto itr = remove_if(beginend(searchVec), [=](ll x)->bool {return x%prime == 0; });searchVec.erase(itr, searchVec.end());} while (prime < sqrtmax);primeVec.reserve(primeVec.size() + searchVec.size());primeVec.insert(primeVec.end(), beginend(searchVec));return primeVec;}
ll sum(vi v) {ll sum=0;Foreach(i,v){sum+=i;}return sum;}
#define ShowAll(v) Foreach(i,v) out(i);
bool isInnerIndex(int kx,int ky,int mx,int my){ return (kx>=0&&kx<mx&&ky>=0&&ky<my); }

int x,y;
vvi box;
int dx[]{0,1,0,-1,1,1,-1,-1};
int dy[]{1,0,-1,0,-1,1,-1,1};
ll s=0;
void dfs(int px,int py){
    box[py][px]=2;
    REP(i,8){
        int nx=px+dx[i];
        int ny=py+dy[i];
        if(isInnerIndex(nx,ny,x,y)){
            if(box[ny][nx]==1)dfs(nx,ny);
        }
    }
    return;
}

int main(){
    vi ans;
    while (cin>>x>>y,(x||y))
    {
        box.clear();
        box.resize(y);
        REP(i,y) REP(n,x) {
            int c;
            cin>>c;
            box[i].pb(c);
        }
        ll s=0;
        REP(i,y)REP(n,x){
            if(box[i][n]==1) {dfs(n,i);s++;}
        }
        ans.pb(s);
    }
    
    ShowAll(ans);
    return 0;
}