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>
using namespace std;
using Graph = vector<vector<int>>;

vector<int> dx = {-1, -1, -1, 0, 1, 1, 1, 0};
vector<int> dy = {-1, 0, 1, 1, 1, 0, -1, -1}; 
int w, h;
int seen[55][55];

void dfs(const Graph &G, int x, int y){
    seen[y][x] = 1;
    for(int i = 0; i < 8; i++){
        if(x + dx[i] < 0 || x + dx[i] >= w || y + dy[i] < 0 || y + dy[i] >= h || G[y + dy[i]][x + dx[i]] == 0) continue;
        if(seen[y + dy[i]][x + dx[i]] == 1) continue;
        dfs(G, x + dx[i], y + dy[i]);
    }
}

int main(){
    while(true){
        cin >> w >> h;
        if(w == 0 && h == 0) break;
        Graph G(h);
        for(int i = 0; i < h; i++){
            for(int j = 0; j < w; j++){
                int k; cin >> k;
                G[i].push_back(k);
            }
        }
        for(int i = 0; i < 55; i++){
          for(int j = 0; j < 55; j++){
            seen[i][j] = 0;
          }
        }
        int cnt = 0; 
        for(int l = 0; l < h; l++){
            for(int m = 0; m < w; m++){
                if(G[l][m] == 1 && seen[l][m] == 0){
                    dfs(G, m, l);
                    cnt++;
                }
            }
        }
        cout << cnt << endl;
    }
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <set>
using namespace std;

struct UnionFind {
        int n;
        vector<int> parent;
        vector<int> rank;
        vector<int> num;
        int find(int x) {
                if (parent[x] == x) return  x;
                return parent[x] = find(parent[x]);
        }
        UnionFind(int n_) {
                n = n_;
                parent.resize(n);
                for (int i = 0; i < n; i ++) parent[i] = i;
                rank.assign(n, 0);
                num.assign(n, 1);
        }
        void unite(int x, int y) {
                if ((x = find(x)) != (y = find(y))) {
                        if (rank[x] < rank[y]) {
                                parent[x] = y;
                                num[y] += num[x];
                        } else {
                                parent[y] = x;
                                if (rank[x] == rank[y]) rank[x] ++;
                                num[x] += num[y];
                        }
                        n --;
                }
        }
        bool same(int x, int y) { return find(x) == find(y); }
        int get() { return n; }
        int get(int x) { return num[find(x)]; }
};

int main() {
        int w, h;
        while (scanf("%d%d", &w, &h), w) {
                vector<vector<int>> s(h, vector<int> (w));
                int lands = 0;
                map<pair<int, int>, int> ptol;
                for (int i = 0; i < h; i ++) {
                        for (int j = 0; j < w; j ++){
                                scanf("%d", &s[i][j]);
                                if (s[i][j]) {
                                        ptol[make_pair(i, j)] = lands;
                                        lands ++;
                                }
                        }
                }
                UnionFind uf(lands);
                for (int i = 0; i < h; i ++) {
                        for (int j = 0; j < w; j ++) {
                                if (s[i][j]) {
                                        if (i - 1 >= 0 && j + 1 < w && s[i - 1][j + 1]) uf.unite(ptol[make_pair(i, j)], ptol[make_pair(i - 1, j + 1)]);
                                        if (j + 1 < w && s[i][j + 1]) uf.unite(ptol[make_pair(i, j)], ptol[make_pair(i, j + 1)]);
                                        if (i + 1 < h && j + 1 < w && s[i + 1][j + 1]) uf.unite(ptol[make_pair(i, j)], ptol[make_pair(i + 1, j + 1)]);
                                        if (i + 1 < h && s[i + 1][j]) uf.unite(ptol[make_pair(i, j)], ptol[make_pair(i + 1, j)]);
                                }
                        }
                }
                printf("%d\n", uf.get());
        }
        return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll=long long;
typedef pair<int,int> P;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
int w,h;
int nx,ny;
void dfs(vector<vector<int>> &G,int a,int b){
    G.at(a).at(b)=0;
    
    for(int k=-1;k<=1;k++){
        for(int s=-1;s<=1;l++){
            nx=a+k;
            ny=b+s;
        if(0<=nx&& nx<h && 0<=ny&& ny<w && G.at(nx).at(ny)==1) dfs(G,nx,ny);
        }
    }
    return ;
}



int main(){
    int w,h;
    cin>>w>>h;
    vector<vector<int>>G(h,vector<int>(w));
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            cin>>G.at(i).at(j);
        }
    }
    int count=0;
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            if(G.at(i).at(j)==1){
                dfs(G,i,j);
                count++;
            }
        }
    }
cout<<count<<endl;
}