#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <cassert>
#include <iostream>
#include <cctype>
#include <sstream>
#include <string>
#include <list>
#include <vector>
#include <queue>
#include <set>
#include <stack>
#include <map>
#include <utility>
#include <numeric>
#include <algorithm>
#include <iterator>
#include <bitset>
#include <complex>
#include <fstream>
using namespace std;
typedef long long ll;
const double EPS = 1e-9;
typedef vector<int> vint;
typedef pair<int, int> pint;
#define rep(i, n) REP(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define MSG(a) cout << #a << " " << a << endl;
#define REP(i, x, n) for(int i = x; i < n; i++)
template<class T> T RoundOff(T a){ return int(a+.5-(a<0)); }
template<class T, class C> void chmax(T& a, C b){ if(a < b) a = b; }
template<class T, class C> void chmin(T& a, C b){ if(b < a) a = b; }
template<class T, class C> pair<T, C> mp(T a, C b){ return make_pair(a, b); }

struct UnionFind
{
	vint data;
	
	UnionFind(int size) : data(size, -1) { }
	
	int unite(int x, int y)
	{
		x = root(x), y = root(y);
		
		if(x != y)
		{
			if(data[y] < data[x]) swap(x, y);
			data[x] += data[y]; data[y] = x;
		}
		
		return x != y;
	}
	
	int root(int x)
	{	return data[x] < 0 ? x : root(data[x]);	}
	
	int size(int x)
	{	return -data[root(x)];	}
	
	bool same(int x, int y)
	{	return root(x) == root(y);	}
};

struct edge{ int u, v, cost;	};

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

int main()
{
    int n, m;
	while(cin >> n >> m && n)
	{
		vector<edge> es(m);
		UnionFind uft(n);
		
		rep(i, m) cin >> es[i].u >> es[i].v >> es[i].cost;
		
		sort(ALL(es), comp);
		
		int res = 0;
		rep(i, m)
		{
			edge e(es[i]);
			
			if(!uft.same(e.u, e.v))
			{
				uft.unite(e.u, e.v);
				res += e.cost;
			}
		}
		
		cout << res << endl;
	}
}