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 <algorithm>
#include <iostream>
#include <string>
#include <cstring>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <deque>
#include <iomanip>
#include <limits>
#include <map>
#include <queue>
#include <stack>
#include <vector>

#define FOR(i,k,n) for(int (i) = (k); (i) < (n); ++(i))
#define rep(i,n) FOR(i,0,n)
#define pb push_back
#define all(v) begin(v), end(v)
#define debug(x) cerr << #x << ": " << x << endl
#define debug2(x,y) cerr << #x << ": " << x << ", " << #y << ": " << y << endl

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<i_i, int> p_i;
typedef vector<int> vi;
typedef vector< vector<int> > vvi;
template<class T> using vv=vector< vector<T> >;
typedef deque<int> di;
typedef deque< deque<int> > ddi;

int dx[3] = {-1,0,1}, dy[3] = {-1,0,1};

int c[55][55] = {};

void dfs(i_i p) {
    c[p.first][p.second] = 0;
    rep(i,3) {
        rep(j,3) {
            if(c[p.first+dx[i]][p.second+dy[j]] == 1) {
                dfs(make_pair(p.first+dx[i], p.second+dy[j]));
            }
        }
    }
}

int main() {
    int w,h;
    while(cin >> w >> h,w) {
        memset(c,0,sizeof(c));
        FOR(i,1,h+1) {
            FOR(j,1,w+1) {
                cin >> c[i][j];
            }
        }
        int sum = 0;
        FOR(i,1,h+1) {
            FOR(j,1,w+1) {
                if(c[i][j] == 1) {
                    dfs(make_pair(i,j));
                    sum += 1;
                }
            }
        }
        cout << sum << endl;
    }
	return 0;
}

C++: #include<bits/stdc++.h>
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
using namespace std;
typedef long long ll;
int INF = (1LL << 30) - 1;
int MOD = 1e9+7;
int H,W;
void dfs(int h,int w,vector<vector<int> > &table){
    //cout << h << " " << w << endl;
    table[h][w] = 0;
    int dx[] = {-1,-1,-1,0 ,0,1 ,1,1};
    int dy[] = {-1,0 ,1 ,-1,1,-1,0,1};
    rep(i,0,8){
        int nx = w + dx[i];
        int ny = h + dy[i];
        if (nx >= W || nx < 0 || ny >= H || ny < 0) continue;
        if(table[ny][nx])dfs(ny,nx,table);
    }
}
main(){
    cin >> W >> H;
    vector< vector<int> > table;
    while(W){
        table = vector< vector<int> > (H,vector<int>(W) );
        rep(i,0,H)rep(j,0,W)cin >> table[i][j];
        rep(i,0,H)rep(j,0,W)cout << table[i][j] << " \n"[j==W-1];
        int cnt = 0;
        rep(i,0,H)rep(j,0,W){
            if(table[i][j] == 1){
                //cout << i << " " << j << endl;
                dfs(i,j,table);
                cnt++;
            }
        }
        cout << cnt << endl;
        cin >> H >> W;
    }
}

C++: #include <cstdio>
#include <iostream>
 
using namespace std;
 
int main(void){
    
    while(1){
        
        int w, h;
        
        cin >> w >> h;
        if(w == 0 && h == 0) break;
        
        int map[52][52] = { {0} };
        int check[52][52] = { {0} };
        
        int i, j;
        for(j=1; j<=h; j++){
            for(i=1; i<=w; i++){
                cin >> map[j][i];
            }
        }
        
        
        int label = 1;
        
        int x, y;
        for(y=1; y<=h; y++){
            for(x=1; x<=w; x++){
                if(map[y][x] == 1){
                    if(check[y][x-1] || check[y-1][x-1] || check[y-1][x] || check[y-1][x+1]){
                        int min;
                        if(check[y][x-1]){
                            min = check[y][x-1];
                        } else {
                            min = 2500;
                        }
                        for(int k=x-1; k<=x+1; k++){
                            if(check[y-1][k] != 0 && check[y-1][k] < min) min = check[y-1][k];
                        }
                        check[y][x] = min;
                    } else {
                        check[y][x] = label;
                        label++;
                    }
                }
            }
        }
        
        
        for(y=h; y>0; y--){
            for(x=w; x>0; x--){
                if(check[y][x]){
                    int min = check[y][x];
                    for(int n=y-1; n<=y+1; n++){
                        for(int k=x-1; k<=x+1; k++){
                            if(check[n][k] != 0 && check[n][k] < min) min = check[n][k];
                        }
                    }
                    check[y][x] = min;
                }
            }
        }
        
        int count = 0;
        
        for(y=1; y<=h; y++){
            for(x=1; x<=w; x++){
                if(count < check[y][x]) count = check[y][x];
            }
        }
        
        cout << count << endl;
        
    }
    
    
    return 0;
}