Go: ///
// File:  1160.go
// Author: ymiyamoto
//
// Created on Sun Mar  4 20:45:57 2018
//
package main

import (
	"fmt"
)

var w, h int
var graph [][]string

func dfs(visited [][]bool, x, y int) {
	visited[x][y] = true

	for i := -1; i <= 1; i++ {
		for j := -1; j <= 1; j++ {
			dx := x + i
			dy := y + j
			if 0 <= dx && dx < h && 0 <= dy && dy < w && graph[dx][dy] == "1" && !visited[dx][dy] {
				dfs(visited, dx, dy)
			}
		}
	}
}

func main() {
	for {
		fmt.Scan(&w, &h)
		if w == 0 && h == 0 {
			break
		}

		graph = make([][]string, h)
		for i := range graph {
			graph[i] = make([]string, w)
		}

		for i := 0; i < h; i++ {
			for j := 0; j < w; j++ {
				var s string
				fmt.Scan(&s)
				graph[i][j] = s
			}
		}

		visited := make([][]bool, h)
		for i := range visited {
			visited[i] = make([]bool, w)
		}

		count := 0
		for i := range graph {
			for j := range graph[i] {
				if graph[i][j] == "1" && !visited[i][j] {
					dfs(visited, i, j)
					count++
				}
			}
		}

		fmt.Println(count)
	}
}

C++: #include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <deque>
#include <algorithm>
#include <utility>
#include <functional>
#include <sstream>
#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <climits>

using namespace std;

inline int toInt(string s) { int v; istringstream sin(s); sin >> v; return v;}
template<class T> inline string toString(T x) { ostringstream sout; sout << x; return sout.str();}

typedef vector<int> vi;
typedef vector<vi>  vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;

#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define EACH(t,i,c) for(t::iretator i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)

const double EPS = 1e-10;

int seamap[52][52];
int num = 0;

void dfs(int x, int y) {
	if(seamap[x][y]) {
		seamap[x][y] = 0;

		if(seamap[x-1][y-1]) {
			dfs(x-1, y-1);
		}
		if(seamap[x][y-1]) {
			dfs(x, y-1);
		}
		if(seamap[x+1][y-1]) {
			dfs(x+1, y-1);
		}
		if(seamap[x-1][y]) {
			dfs(x-1, y);
		}
		if(seamap[x+1][y]) {
			dfs(x+1, y);
		}
		if(seamap[x-1][y+1]) {
			dfs(x-1, y+1);
		}
		if(seamap[x][y+1]) {
			dfs(x, y+1);
		}
		if(seamap[x+1][y+1]) {
			dfs(x+1, y+1);
		}
	}
}


int main() {
	int w, h;

	REP(i, 52) {
		REP(j, 52) {
			seamap[i][j] = 0;
		}
	}

	while(cin >> w >> h, (w!=0 || h!=0)) {
		FOR(i, 0, 52) {
			FOR(j, 0, 52) {
				seamap[i][j] = 0;
			}
		}

		FOR(i, 1, h+1) {
			FOR(j, 1, w+1) {
				cin >> seamap[i][j];
			}
		}

		num = 0;

		FOR(i, 1, 50) {
			FOR(j, 1, 50) {
				if(seamap[i][j]) {
					num++;
					dfs(i, j);
				}
			}
		}

		cout << num << endl;
	}

	return 0;
}

C++: #include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<cmath>
#include<stdio.h>
#include<queue>
#include <climits>
#include <map>
#include <set>
const int mod = 1e9 + 7;
const long long INF = 1LL << 60;
using namespace std;
typedef long long ll;

int w,h;
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};

void dfs(int x,int y)
{
    c[x][y] = 0;
    for(int i = 0; i < 8; i++){
        int nx = x + dx[i] , ny = y + dy[i];
        if(0 <= nx && nx < w && 0 <= ny && ny < h && c[nx][ny] == 1){
            dfs(nx,ny);
        }
    }
    return;
}


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

C++: #include <iostream>
using namespace std;

int w, h;
int field[60][60];

void dfs(int x, int y) {
    field[x][y] = 0;

    for (int i = -1; i <= 1; i++) {
        for (int j = -1; j <= 1; j++) {
            int dx = x + i, dy = y + j;
            if (dx < 0 || dx >= h || dy < 0 || dy >= w) continue;
            if (field[dx][dy] == 0) continue;
            dfs(dx, dy);
        }
    }
}

int main() {
    while (1) {
        cin >> w >> h;
        if (w == 0 && h == 0) break;

        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                cin >> field[i][j];
            }
        }

        int cnt = 0;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                if (field[i][j] == 0) continue;
                dfs(i, j);
                cnt++;
            }
        }

        cout << cnt << endl;
    }

    return 0;
}

C++: #include <bits/stdc++.h>  
#define rep(i, n) for(int i=0; i<(int)(n); ++i)
#define cout(val) cout << (val) << endl
using namespace std;
typedef long long LL;

int main(){
    int w, h, t0, t1, result, temp;
    pair<int, int> cur;
    vector<int> dx = {1, 1, 1, 0, 0, -1, -1, -1};
    vector<int> dy = {1, 0, -1, 1, -1, 1, 0, -1};
    while(true){
        cin >> w >> h;
        if(w == 0 && h == 0) break;
        vector<LL> c(h);
        vector<LL> seen(h);
        vector<pair<int, int>> f;
        rep(i, h) rep(j, w){
            cin >> temp;
            c[i] |= (LL)temp<<j;
            if(temp) f.push_back(make_pair(i, j));
        }
        result = 0;
        stack<pair<int, int>> stk;
        for(auto &&pos : f){
            if(!(seen[pos.first]&1LL<<pos.second)) ++result;
            stk.push(make_pair(pos.first, pos.second));
            while(!stk.empty()){
                cur = stk.top();
                stk.pop();
                rep(i, 8){
                    t0 = cur.first + dy[i];
                    t1 = cur.second + dx[i];
                    if(t0==-1 || t0==h || t1==-1 || t1==w || seen[t0]&1LL<<t1 || !(c[t0]&1LL<<t1)) continue;
                    stk.push(make_pair(t0, t1));
                    seen[t0] |= 1LL<<t1;
                }
            }
        }
        cout(result);
    }
}

C++: #include <iostream>
using namespace std;
void dfs(int,int);
int data[52][52];
int main(){
  int w,h,i,j,cnt;
  while(1){
    cnt=0;
    cin >> w >> h;
    if(w==0&&h==0) break;
    for(i=0;i<=h+1;i++){
      for(j=0;j<=w+1;j++){
	data[i][j]=0;
      }
    }
    for(i=1;i<=h;i++){
      for(j=1;j<=w;j++){
	cin >> data[i][j];
      }
    }
    for(i=1;i<=h;i++){
      for(j=1;j<=w;j++){
        if(data[i][j]==1){
	  dfs(i,j);
	  cnt++;
	}
      }
    }
    cout << cnt << endl;
  }
  return 0;
}
void dfs(int i,int j){
  if(data[i][j]==0) return ;
  data[i][j]=0;
  dfs(i-1,j);
  dfs(i+1,j);
  dfs(i,j-1);
  dfs(i,j+1);
  dfs(i-1,j-1);
  dfs(i-1,j+1);
  dfs(i+1,j-1);
  dfs(i+1,j+1);
}

C++: #include <iostream>
using namespace std;

int c[50][50];
int w, h;

void dfs(int x, int y) {
  c[y][x] = 0;
  for (int i = -1; i <= 1; i++) {
    for (int j = -1; j <= 1; j++) {
      int nx = x + i;
      int ny = y + j;
      if (c[ny][nx] == 1 && 0 <= nx && nx < w && 0 <= ny && ny < h)
	dfs(nx, ny);
    }
  }
}

int search() {
  int count = 0;
  for (int i = 0; i < h; i++) {
    for (int j = 0; j < w; j++) {
      if (c[i][j] == 1) {
	dfs(j, i);
	count++;
      }
    }
  }
  return count;
}

int main() {
  while (true) {
    cin >> w >> h;
    if (w == 0 && h == 0) return 0;

    for (int i = 0; i < h; i++)
      for (int j = 0; j < w; j++)
	cin >> c[i][j];

    int ans = search();
    cout << ans << endl;
  }
}