Go: package main

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

var sc = bufio.NewScanner(os.Stdin)
var route [][]int

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func dfs(h, w int) {
	if route[h][w] == 0 {
		return
	}

	route[h][w] = 0
	for _, x := range []int{-1, 0, 1} {
		for _, y := range []int{-1, 0, 1} {
			if route[h+x][w+y] == 0 {
				continue
			}
			dfs(h+x, w+y)
		}
	}
}

func main() {
	writer := bufio.NewWriter(os.Stdout)
	for {
		w, h := scanInt(), scanInt()
		if w == 0 && h == 0 {
			break
		}

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

		total := 0
		for i := 1; i <= h; i++ {
			for j := 1; j <= w; j++ {
				if route[i][j] == 1 {
					total++
					dfs(i, j)
				}
			}
		}
		fmt.Fprintln(writer, total)
	}
	writer.Flush()
}

C++: #define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); i++)
#define YES(n) cout << ((n) ? "YES" : "NO") << endl
#define Yes(n) cout << ((n) ? "Yes" : "No") << endl

using namespace std;

typedef long long ll;
typedef pair<int, int> P;
typedef pair<ll, ll> LP;

const int MOD = 1e9 + 7;
const int INF = 1e9;
const ll LINF = 1e18;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};
const int ddx[8] = {1, 1, 0, -1, -1, -1, 0, 1};
const int ddy[8] = {0, 1, 1, 1, 0, -1, -1, -1};

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

int lcm(int a, int b) { return a * b * gcd(a, b); }

bool compareP(pair<int, int> a, pair<int, int> b) {
    if (a.second != b.second) {
        return a.second < b.second;
    } else {
        return a.first < b.first;
    }
}

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

void dfs(int h2, int w2) {
    mp[h2][w2] = 0;
    rep(i, 8) {
        int nw = w2 + ddx[i];
        int nh = h2 + ddy[i];
        if (nw >= 0 && nw < w && nh >= 0 && nh < h && mp[nh][nw] == 1)
            dfs(nh, nw);
    }
}

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

C++: /*
　　こんにちは。あたしはｶｳｶﾞｰﾙ。
　　redcoderになるためAtCoderを巡る旅をしてます。

　　　 　 ＿_
　　　 ヽ|＿_|ノ　　　　ﾓｫ
　　　　||‘‐‘||ﾚ　　_)_, ―‐ 、
　　　　/(Ｙ (ヽ＿ /・ ヽ　　 ￣ヽ
　　　　∠ ＿ ゝ　 ｀^ヽ ﾉ.::::_(ノヽ
　　　　 _/ヽ　 　　  /ヽ￣￣/ヽ
*/

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define dump(x) cout << #x << " = " << (x) << endl
#define YES(n) cout << ((n) ? "YES" : "NO") << endl
#define Yes(n) cout << ((n) ? "Yes" : "No") << endl
#define POSSIBLE(n) cout << ((n) ? "POSSIBLE" : "IMPOSSIBLE") << endl
#define Possible(n) cout << ((n) ? "Possible" : "Impossible") << endl

#define rep(i, n) REP(i, 0, n)                  // 0, 1, ..., n-1
#define REP(i, x, n) for(int i = x; i < n; i++) // x, x + 1, ..., n-1
#define FOREACH(x, a) for(auto &(x) : (a))

#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()

#define COUT(x) cout << (x) << endl

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;
vector<vector<int>> field;

void dfs(int h, int w) {
    field[h][w] = 0;

    for(int dh = -1; dh <= 1; ++dh) {
        for(int dw = -1; dw <= 1; dw++) {
            int nh = h + dh, nw = w + dw;

            if(nh < 0 || nh >= H || nw < 0 || nw >= W) continue;
            if(field[nh][nw] == 0) continue;

            dfs(nh, nw);
        }
    }
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    while(cin >> W >> H) {
        if(H == 0 || W == 0) break;
        field.assign(H, vector<int>(W, 0));
        rep(h, H) rep(w, W) cin >> field[h][w];

        int count = 0;
        rep(h, H) {
            rep(w, W) {
                if(field[h][w] == 0) continue;
                dfs(h, w);
                ++count;
            }
        }
        cout << count << endl;
    }
}

C++: #include <iostream>

using namespace std;

int w, h;
int c[55][55], ans;

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

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

C++: //8方向
//0が海、1が島

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

// 入力
int H, W;
vector<vector<int>> field;

// 探索
void dfs(int h, int w) {
	field[h][w] = 0;

	// 八方向を探索
	for (int dh = -1; dh <= 1; ++dh) {
		for (int dw = -1; dw <= 1; ++dw) {
			//if(dh*dw!=0) continue; //4方向にするときはここを有効に
			int nh = h + dh, nw = w + dw;

			// 場外アウトしたり、0 だったりはスルー
			if (nh < 0 || nh >= H || nw < 0 || nw >= W) continue;
			if (field[nh][nw] == 0) continue;

			// 再帰的に探索
			dfs(nh, nw);
		}
	}
}

int main() {
	// 入力受け取り
	while (cin >> W >> H) {
		if (H == 0 || W == 0) break;
		field.assign(H, vector<int>(W, 0));
		for (int h = 0; h < H; ++h) {
			for (int w = 0; w < W; ++w) cin >> field[h][w];
		}

		// 探索開始
		int count = 0;
		for (int h = 0; h < H; ++h) {
			for (int w = 0; w < W; ++w) {
				if (field[h][w] == 0) continue; // 残島じゃなかったらスルー
				dfs(h, w);
				++count;
			}
		}
		cout << count << endl;
	}
}

C++: #include<iostream>
#include<algorithm>
#include<cmath>
#include<iomanip>
#include<map>
using namespace std;
int w,h,c[50][50];

void dfs(int y,int x) {
  c[y][x]=0;
  for(int dy=-1; dy<=1; dy++) {
    for(int dx=-1; dx<=1; dx++) {
      int nx=x+dx,ny=y+dy;
      if(nx>=0&&nx<w&&ny>=0&&ny<h&&c[ny][nx]==1) {
        dfs(ny,nx);
      }
    }
  }
}
int main() {
  while(cin >> w >> h) {
    if(w==0&&h==0) {
      return 0;
    }
    else {
      int ans=0;
      for(int i=0; i<h; i++) {
        for(int j=0; j<w; j++) {
          cin >> c[i][j];
        }
      }
      for(int i=0; i<h; i++) {
        for(int j=0; j<w; j++) {
          if(c[i][j]==1) {
            dfs(i,j);
            ans++;
          }
        }
      }
      cout << ans << endl;
    }
  }
}