Go: // AOJ 1160: How Many Islands? http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160

package main

import (
	"bufio"
	"container/list"
	"fmt"
	"os"
	"strconv"
)

var SEA = 0
var LAND = 1

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func discoverIslands(M, V [][]int, H, W int) int {
	// 島を探す
	queue := list.New()
	islands := 0
	for i := 1; i <= H; i++ {
		for j := 1; j <= W; j++ {
			// 訪問済みの土地ならスキップ
			if V[i][j] == 1 {
				continue
			}

			// 訪問中の土地が海なら訪問済みにしてスキップ
			if M[i][j] == SEA {
				V[i][j] = 1
				continue
			}

			// 未訪問の陸地が見つかったので
			// 島の数を1つ増やし、この陸地から辿れる陸地を訪問していく
			islands++
			queue.PushBack([]int{i, j})

			for queue.Len() > 0 {
				cur := queue.Remove(queue.Front()).([]int)
				h, w := cur[0], cur[1]
				if V[h][w] == 1 {
					continue
				}
				V[h][w] = 1

				// 全方向に未訪問の陸地がないか探索
				for v := -1; v <= 1; v++ {
					for l := -1; l <= 1; l++ {
						dh := h + v
						dw := w + l
						if M[dh][dw] == LAND && V[dh][dw] == 0 {
							queue.PushBack([]int{dh, dw})
						}
					}
				}
				/*
					if M[h-1][w] == LAND {
						queue.PushBack([]int{h - 1, w})
					}
					if M[h-1][w+1] == LAND {
						queue.PushBack([]int{h - 1, w + 1})
					}
					if M[h][w+1] == LAND {
						queue.PushBack([]int{h, w + 1})
					}
					if M[h+1][w+1] == LAND {
						queue.PushBack([]int{h + 1, w + 1})
					}
					if M[h+1][w] == LAND {
						queue.PushBack([]int{h + 1, w})
					}
					if M[h+1][w-1] == LAND {
						queue.PushBack([]int{h + 1, w - 1})
					}
					if M[h][w-1] == LAND {
						queue.PushBack([]int{h, w - 1})
					}
					if M[h-1][w-1] == LAND {
						queue.PushBack([]int{h - 1, w - 1})
					}
				*/
			}
		}
	}
	return islands
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	for {
		W, H := nextInt(sc), nextInt(sc)

		if W == 0 && H == 0 {
			break
		}
		// Initialize map and visted list
		M := make([][]int, H+2)
		V := make([][]int, H+2)
		for i := 0; i < H+2; i++ {
			M[i] = make([]int, W+2)
			V[i] = make([]int, W+2)
		}
		for i := 1; i <= H; i++ {
			for j := 1; j <= W; j++ {
				M[i][j] = nextInt(sc)
			}
		}

		islands := discoverIslands(M, V, H, W)

		fmt.Println(islands)
	}
}

C++: #include <bits/stdc++.h>
using namespace std;

using i64 = int64_t;

#define rep(i, x, y) for (i64 i = i64(x), i##_max_for_repmacro = i64(y); i < i##_max_for_repmacro; ++i)
#define debug(x) #x << "=" << (x)

#ifdef DEBUG
#define _GLIBCXX_DEBUG
#define print(x) std::cerr << debug(x) << " (L:" << __LINE__ << ")" << std::endl
#else
#define print(x)
#endif

template <i64 p>
class fp {
    public:
    i64 x;
    fp() : x(0) {}
    fp(i64 x_) : x((x_ % p + p) % p) {}
    fp operator+() const { return fp(x); }
    fp operator-() const { return fp(-x); }
    fp& operator+=(const fp& y) {
        x += y.x;
        if (x >= p) x -= p;
        return *this;
    }
    fp& operator-=(const fp& y) { return *this += -y; }
    fp& operator*=(const fp& y) {
        x = x * y.x % p;
        return *this;
    }
    fp& operator/=(const fp& y) { return *this *= fp(inverse(y.x)); }
    fp operator+(const fp& y) const { return fp(x) += y; }
    fp operator-(const fp& y) const { return fp(x) -= y; }
    fp operator*(const fp& y) const { return fp(x) *= y; }
    fp operator/(const fp& y) const { return fp(x) /= y; }
    bool operator==(const fp& y) const { return x == y.x; }
    bool operator!=(const fp& y) const { return !(*this == y); }
    i64 extgcd(i64 a, i64 b, i64& x, i64& y) {
        i64 d = a;
        if (b != 0) {
            d = extgcd(b, a % b, y, x);
            y -= (a / b) * x;
        } else {
            x = 1;
            y = 0;
        }
        return d;
    }
    i64 inverse(i64 a) {
        i64 x, y;
        extgcd(a, p, x, y);
        return (x % p + p) % p;
    }
};

template <i64 p>
i64 abs(const fp<p>& x) { return x.x; }

template <i64 p>
istream& operator>>(istream& is, fp<p>& x) {
    is >> x.x;
    return is;
}

template <i64 p>
ostream& operator<<(ostream& os, const fp<p>& x) {
    os << x.x;
    return os;
}

template <typename T, typename U>
ostream& operator<<(ostream& os, const pair<T, U>& p) {
    os << "(" << p.first << ", " << p.second << ")";
    return os;
}

template <typename T>
ostream& operator<<(ostream& os, const vector<T>& vec) {
    os << "[";
    for (const auto& v : vec) {
        os << v << ",";
    }
    os << "]";
    return os;
}

template <typename T>
bool chmin(T& a, const T& b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

template <typename T>
bool chmax(T& a, const T& b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template <typename A, typename T, size_t size>
void fill(A (&ary)[size], const T& val) {
    fill((T*)ary, (T*)(ary + size), val);
}

// x未満の要素の個数を返す
template <typename T>
i64 count_less(const vector<T>& v, T x) {
    return lower_bound(begin(v), end(v), x) - begin(v);
}

// x以下の要素の個数を返す
template <typename T>
i64 count_less_or_equal(const vector<T>& v, T x) {
    return upper_bound(begin(v), end(v), x) - begin(v);
}

// xより大きい要素の個数を返す
template <typename T>
i64 count_greater(const vector<T>& v, T x) {
    return end(v) - upper_bound(begin(v), end(v), x);
}

// x以上の要素の個数を返す
template <typename T>
i64 count_greater_or_equal(const vector<T>& v, T x) {
    return end(v) - lower_bound(begin(v), end(v), x);
}

// x未満の要素のうち最大のものを返す
template <typename T>
T max_less(const vector<T>& v, T x) {
    return *(lower_bound(begin(v), end(v), x) - 1);
}

// x以下の要素のうち最大のものを返す
template <typename T>
T max_less_or_equal(const vector<T>& v, T x) {
    return *(upper_bound(begin(v), end(v), x) - 1);
}

// xより大きい要素のうち最小のものを返す
template <typename T>
T min_greater(const vector<T>& v, T x) {
    return *upper_bound(begin(v), end(v), x);
}

// x以上の要素のうち最小のものを返す
template <typename T>
T min_greater_or_equal(const vector<T>& v, T x) {
    return *lower_bound(begin(v), end(v), x);
}

constexpr int inf = 1.01e9;
constexpr i64 inf64 = 4.01e18;
constexpr long double eps = 1e-9;

// 実数値のn分探索のループ回数の上限(2分探索なら50でも十分かもしれない)
constexpr i64 max_loop = 100;

long double tolerance(const long double& a, const long double& b, const long double& epsilon = eps) {
    return epsilon * max({1.l, abs(a), abs(b)});
}

// a<0なら-1, a==0なら0, a>0なら1
int sgn(const long double a, const long double& epsilon = eps) {
    return (a > epsilon) - (a < -epsilon);
}

// a<bなら-1, a==bなら0, a>bなら1
int compare(const long double& a, const long double& b, const long double& epsilon = eps, bool is_relative = true) {
    return sgn(a - b, is_relative ? tolerance(a, b, epsilon) : epsilon);
}

// a==bか?
bool is_equal(const long double& a, const long double& b, const long double& epsilon = eps, bool is_relative = true) {
    return compare(a, b, epsilon, is_relative) == 0;
}

// a<bか?
bool is_less(const long double& a, const long double& b, const long double& epsilon = eps, bool is_relative = true) {
    return compare(a, b, epsilon, is_relative) == -1;
}

// a<=bか?
bool is_less_or_equal(const long double& a, const long double& b, const long double& epsilon = eps, bool is_relative = true) {
    return compare(a, b, epsilon, is_relative) <= 0;
}

// a>bか?
bool is_greater(const long double& a, const long double& b, const long double& epsilon = eps, bool is_relative = true) {
    return compare(a, b, epsilon, is_relative) == 1;
}

// a>=bか?
bool is_greater_or_equal(const long double& a, const long double& b, const long double& epsilon = eps, bool is_relative = true) {
    return compare(a, b, epsilon, is_relative) >= 0;
}

void solve() {
    //constexpr i64 mod = 1'000'000'007;
    while(true) {
        i64 w, h;
        cin >> w >> h;
        if(w==0 and h == 0) break;
        vector<vector<int>> c(h, vector<int>(w));
        rep(i, 0, h) {
            rep(j, 0, w) {
                cin >> c[i][j];
            }
        }

        const vector<i64> dy={0,-1,-1,-1,0,1,1,1};
        const vector<i64> dx={1,1,0,-1,-1,-1,0,1};
        vector<vector<bool>> visited(h,vector<bool>(w));
        function<void(i64,i64)> dfs=[&](i64 i,i64 j){
            visited[i][j]=true;
            rep(k,0,dy.size()){
                i64 ni=i+dy[k],nj=j+dx[k];
                if(ni<0 or h<=ni or nj<0 or w<=nj or c[ni][nj]==0 or visited[ni][nj]) continue;
                dfs(ni,nj);
            }
        };

        i64 ans=0;
        rep(i,0,h) rep(j,0,w){
            if(visited[i][j] or c[i][j]==0) continue;
            ++ans;
            dfs(i,j);
        }

        cout << ans << endl;
    }
}

int main() {
    std::cin.tie(0);
    std::ios::sync_with_stdio(false);
    cout.setf(ios::fixed);
    cout.precision(16);
    solve();
    return 0;
}