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

typedef ostringstream OSS;
typedef istringstream ISS;

typedef long long LL;
typedef pair<int, int> PII;

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<LL> VLL;
typedef vector<VLL> VVLL;
typedef vector<string> VS;
typedef vector<VS> VVS;
typedef vector<bool> VB;
typedef vector<VB> VVB;

typedef vector<PII> VPII;

#define fst first
#define snd second
#define MP make_pair
#define PB push_back
#define ALL(x) (x).begin(),(x).end()
#define RANGE(x,y,maxX,maxY) (0 <= (x) && 0 <= (y) && (x) < (maxX) && (y) < (maxY))
#define DUMP( x ) cerr << #x << " = " << ( x ) << endl

template < typename T > inline T fromString(const string &s) { T res; ISS iss(s); iss >> res; return res; };
template < typename T > inline string toString(const T &a) { OSS oss; oss << a; return oss.str(); };

const int INF = 0x3f3f3f3f;
const LL INFL = 0x3f3f3f3f3f3f3f3fLL;
const int DX[]={1,0,-1,0},DY[]={0,-1,0,1};

/***** Union-Find *****/

const int MAX_N = 10000;
int Par[MAX_N];
int Rank[MAX_N];

void union_find_init(int n){
	for(int i=0; i<n; ++i){
		Par[i] = i;
		Rank[i] = 0;
	}
}

int find(int x){
	if(Par[x] == x){
		return x;
	}else {
		return Par[x] = find(Par[x]);
	}
}

void unite(int x, int y){
	x = find(x);
	y = find(y);

	if(x == y)
		return ;

	if(Rank[x] < Rank[y]){
		Par[x] = y;
	} else{
		Par[y] = x;
		if(Rank[x] == Rank[y]){
			++Rank[x];
		}
	}
}

bool same(int x, int y){
	return find(x) == find(y);
}

/***** /Union-Find *****/

/***** Kruskal *****/

struct edge {
	int from,
		to,
		cost;
};

bool comp(const edge& e1, const edge& e2){
	return e1.cost < e2.cost;
}

const int MAX_E = 10000;
edge es[MAX_E];
int V, E;

int kruskal(void){
	sort(es, es + E, comp);
	union_find_init(V);

	int res = 0;
	for(int i=0; i<E; ++i){
		edge e = es[i];
		if(!same(e.from, e.to)){
			unite(e.from, e.to);
			res += e.cost;
		}
	}

	return res;
}

/***** /Kruskal *****/

int main(void) {
	while (cin >> V >> E, V) {
		E *= 2;
		for (int i = 0; i < E / 2; i++) {
			int a, b, cost;
			cin >> a >> b >> cost;
			es[i * 2].from = a;
			es[i * 2].to = b;
			es[i * 2].cost = cost;
			es[i * 2 + 1].from = b;
			es[i * 2 + 1].to = a;
			es[i * 2 + 1].cost = cost;
		}

		int res = kruskal();

		cout << res << endl;
	}

	return 0;
}