Go: package main

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

var (
	readString func() string
	readBytes  func() []byte
	stdout     *bufio.Writer
)

func init() {
	readString, readBytes = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) (func() string, func() []byte) {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), math.MaxInt32)
	r.Split(bufio.ScanWords)

	f1 := func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
	f2 := func() []byte {
		return []byte(f1())
	}
	return f1, f2
}

func readInt() int {
	return int(readInt64())
}

func readInt64() int64 {
	i, err := strconv.ParseInt(readString(), 10, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(readString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

func printf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(stdout, f, args...)
}

func println(args ...interface{}) (int, error) {
	return fmt.Fprintln(stdout, args...)
}

func eprintln(args ...interface{}) (int, error) {
	return fmt.Fprintln(os.Stderr, args...)
}

func eprintf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(os.Stderr, f, args...)
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func min64(a, b int64) int64 {
	if a < b {
		return a
	}
	return b
}

func max(a, b int) int {
	if a < b {
		return b
	}
	return a
}

func max64(a, b int64) int64 {
	if a < b {
		return b
	}
	return a
}

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

func abs64(a int64) int64 {
	if a < 0 {
		return -a
	}
	return a
}

func gcd(a, b int) int {
	if b == 0 {
		return a
	}
	return gcd(b, a%b)
}

func gcd64(a, b int64) int64 {
	if b == 0 {
		return a
	}
	return gcd64(b, a%b)
}

// readString() string
// readInt() int
// readInt64() int64
// readFloat64() float64

// -----------------------------------------------------------------------------

func main() {
	defer stdout.Flush()

	for {
		ans, ok := solve()
		if !ok {
			break
		}
		println(ans)
	}

}

func solve() (int, bool) {
	w := readInt()
	h := readInt()
	if w == 0 && h == 0 {
		return 0, false
	}

	c := make([][]int, h+2)
	c[0] = make([]int, w+2)
	c[h+1] = make([]int, w+2)
	for i := 1; i-1 < h; i++ {
		c[i] = make([]int, w+2)
		for j := 1; j-1 < w; j++ {
			c[i][j] = readInt()
		}
	}

	var ans int
	for i := 1; i-1 < h; i++ {
		for j := 1; j-1 < w; j++ {
			if 0 < c[i][j] {
				ans++
				dfs(c, i, j)
			}
		}
	}
	return ans, true
}

func dfs(c [][]int, y, x int) {
	c[y][x] = 0
	dx := []int{-1, 0, 1, -1, 1, -1, 0, 1}
	dy := []int{-1, -1, -1, 0, 0, 1, 1, 1}
	for i := range dx {
		nx := x + dx[i]
		ny := y + dy[i]
		if 0 < c[ny][nx] {
			dfs(c, ny, nx)
		}
	}
}

// -----------------------------------------------------------------------------

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

#define rep(i,n) for(int i=0;i<n;i++)
#define REP(n) rep(i,n)
#define all(n) n.begin(),n.end()

const int MAXW = 52, MAXH = 52, RIKU = 1, UMI = 0;

int tile[MAXH][MAXW];
int dx[] = {-1, 0, 1, -1, 1, -1, 0, 1};
int dy[] = {-1, -1, -1, 0, 0, 1, 1, 1};
int w, h;

int solve(int x, int y)
{
    if(tile[x][y] == RIKU)
    {
        tile[x][y] = UMI;
        
        REP(8)if( x+dx[i]>=0 && x+dx[i] < w && y+dy[i] >= 0 && y+dy[i] < h)
            solve(x+dx[i], y+dy[i]);

        return 1;
    }
    return 0;
}

int main()
{
    while(cin >> w >> h && (w || h))
    {
        memset(tile, 0, sizeof(tile));
        rep(j,h)rep(i,w) cin >> tile[i][j];

        int ans = 0;
        rep(j,h)rep(i,w) ans += solve(i,j);

        cout << ans << endl;
    }
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=n-1;i>=0;i--)
#define lper(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define ins insert
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[8]={1,0,-1,0,1,1,-1,-1};
const ll dx[8]={0,-1,0,1,1,-1,1,-1};
ll modfac(ll a){
    ll ans=1;
    while(a>1){
        ans*=a;
        ans%=1000000007;
        a--;
    }
    return ans;
}
ll modinv(ll a,ll m) {
    ll b = m, u = 1, v = 0;
    while (b) {
        ll t = a / b;
        a -= t * b; swap(a, b);
        u -= t * v; swap(u, v);
    }
    u %= m; 
    if (u < 0) u += m;
    return u;
}
struct UnionFind {
    vector<int> par;
    
    UnionFind(int n) : par(n, -1) {}

    int root(int x) {
        if (par[x] < 0) return x;
        else return par[x] = root(par[x]);
    }
    
    bool same(int x, int y) {
        return root(x) == root(y);
    }
    
    bool merge(int x, int y) {
        x = root(x); y = root(y);
        if (x == y) return false;
        if (par[x] > par[y]) swap(x, y);
        par[x] += par[y];
        par[y] = x;
        return true;
    }
    
    int size(int x) {
        return -par[root(x)];
    }
};
ll modpow(ll a, ll n, ll mod) {
    ll res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
ll h,w;
vvl field(h,vl(w));
void dfs(ll y,ll x){
    field[y][x]=0;
    rep(i,8){
        ll ny=y+dy[i],nx=x+dx[i];
        if(ny<0||nx<0||ny>=h||nx>=w)continue;
        if(field[ny][nx]==1){
            dfs(ny,nx);
        }
    }
}
int main(){
    while(true){
        ll ans=0;
        cin >> w >>h;
        if(w==0&&h==0)break;
        field.assign(h,vl(w));
        rep(i,h){
            rep(j,w)cin >> field[i][j];
        }
        rep(i,h){
            rep(j,w){
                if(field[i][j]==1){
                    dfs(i,j);
                    ans++;
                }
            }
        }
        cout <<ans <<endl;
    }
}

C++: #include<iostream>
#include<vector>
#include<stdio.h>
using namespace std;
#define DUMP(x)  cerr << #x << " = " << (x) << endl;
#define DEBUG(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

vector<vector<int> > map;
vector<vector<bool> > reach;
int w,h;

void dfs(int i, int j){
    if((reach[i][j]) or (map[i][j]==0))
        return;
    reach[i][j] = true;
    if(0<i && 0<j) dfs(i-1,j-1);
    if(0<i) dfs(i-1,j);
    if(0<i && j<w-1) dfs(i-1,j+1);
    if(0<j) dfs(i, j-1);
    if(j<w-1) dfs(i, j+1);
    if(i<h-1 && 0<j) dfs(i+1,j-1);
    if(i<h-1) dfs(i+1,j);
    if(i<h-1 && j<w-1) dfs(i+1,j+1);
}

int main(){

    while((cin >> w >> h) && (w>0 && h>0)){
        int res=0;
        for (int i = 0; i < h; i++) {
            vector<int> temp(w,0);
            for (int j = 0; j < w; j++)
                cin >> temp[j];
            map.push_back(temp);
        }
        for (int i = 0; i < h; i++){
            vector<bool> temp(0,false);
            reach.push_back(temp);
        }
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                if(map[i][j]==1 && !reach[i][j]){
                    res++;
                    dfs(i,j);
                }
            }
        }
        cout << res << endl;
        map.clear();
        reach.clear();

    }
    return 0;
}