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<iostream>
#include<vector>
#include<stack>
using namespace std;

typedef long long itemType;

struct node
{long long v; struct node *next;};

void visit(stack<long long> stack, long long k, struct node *z, struct node **adj, long long id, long long val[]){
    struct node *t;
    t = new node;
    stack.push(k);
    while(!stack.empty()){
        k = stack.top();
        stack.pop();
        val[k] = ++id;
        for(t = adj[k]; t != z; t = t -> next){
            if(val[t -> v] == 0){
                stack.push(t -> v);
                val[t -> v] = -1;
            }
        }
    }
}

void search(stack<long long>stack, long long V, struct node *z, struct node **adj, long long id, long long val[], long long &comp, vector<vector<bool> > c, long long w){
    long long k;
    for(k = 1; k <= V; k++) val[k] = 0;
    for(k = 1; k <= V; k++){
        if(val[k] == 0){
            if(c[(k-1)/w + 1][((k-1)%w) + 1]) comp++;
            visit(stack, k, z, adj, id, val);
        }
    }
}

int main(){
    long long w, h;
    vector<bool> sub;
    bool c_sub;
    long long i, j;
    for(i = 0; i <= 50; i++){
        sub.push_back(0);
    }
    vector<vector<bool> > c;
    for(i = 0; i <= 50; i++){
        c.push_back(sub);
    }
    long long V;
    struct node *z;
    z = new node;
    z -> next = z;
    struct node *adj[2501];
    struct node *t;
    long long x, y;
    while(1){

        //input
        cin >> w >> h;
        if(w == 0 && h == 0) break;
        for(i = 1; i <= h; i++){
            for(j = 1; j <= w; j++){
                cin >> c_sub;
                c[i][j] = c_sub;
            }
        }

        //adjacency list representation
        V = w * h;
        stack<long long> stack;
        for(i = 1; i <= V; i++){
            adj[i] = z;
        }
        for(j = 1; j <= w; j++){
            for(i = 1; i <= h-1; i++){
                if(c[i][j] & c[i+1][j]){
                    x = (i-1)*w + j;
                    y = i*w + j;
                    t = new node;
                    t -> v = x;
                    t -> next = adj[y];
                    adj[y] = t;
                    t = new node;
                    t -> v = y;
                    t -> next = adj[x];
                    adj[x] = t;
                    
                }
            }
        }
        
        for(i = 1; i <= h; i++){
            for(j = 1; j <= w-1; j++){
                if(c[i][j] & c[i][j+1]){
                    x = (i-1)*w + j;
                    y = (i-1)*w + j+1;
                    t = new node;
                    t -> v = x;
                    t -> next = adj[y];
                    adj[y] = t;
                    t = new node;
                    t -> v = y;
                    t -> next = adj[x];
                    adj[x] = t;
                    
                }
            }
        }
        for(i = 1; i <= h-1; i++){
            for(j = 1; j <= w-1; j++){
                if(c[i][j] & c[i+1][j+1]){
                    x = (i-1)*w + j;
                    y = i*w + j+1;
                    t = new node;
                    t -> v = x;
                    t -> next = adj[y];
                    adj[y] = t;
                    t = new node;
                    t -> v = y;
                    t -> next = adj[x];
                    adj[x] = t;
                    
                }
            }
        }
        for(i = 1; i <= h-1; i++){
            for(j = 1; j <= w-1; j++){
                if(c[i+1][j] & c[i][j+1]){
                    x = i*w + j;
                    y = (i-1)*w + j+1;
                    t = new node;
                    t -> v = x;
                    t -> next = adj[y];
                    adj[y] = t;
                    t = new node;
                    t -> v = y;
                    t -> next = adj[x];
                    adj[x] = t;
                    
                }
            }
        }

        //depth first search
        long long id = 0;
        long long val[V + 1];
        long long comp = 0;
        search(stack, V, z, adj, id, val, comp, c, w);
        cout << comp << endl;
    }

    return 0;
}

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

using namespace std;

int c[50][50];

int dx[8] = {-1,-1,-1, 0, 0, 1, 1, 1};
int dy[8] = {-1, 0, 1,-1, 1,-1, 0, 1};

int ret;

int w,h;

void dfs(int x,int y){
	if(c[x][y] == 0) return;
	c[x][y] = 0;
	for(int i=0;i<8;i++){
		if(x+dx[i] < 0 || x+dx[i] >= w) continue;
		if(y+dy[i] < 0 || y+dy[i] >= h) continue;
		dfs(x+dx[i],y+dy[i]);
	}
}

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