#include "bits/stdc++.h"
//#include <boost/multiprecision/cpp_int.hpp>
//using namespace boost::multiprecision;
const int mx = 1e6+5;
const long int inf = 2e9;
typedef long long ll;
#define rep(i,n) for(i=0;i<n;i++)
#define repp(i,a,b) for(i=a;i<=b;i++)
#define pii pair<int,int>
#define vpii vector< pii >
#define vi vector<int>
#define vll vector<ll>			
#define r(x) scanf("%d",&x)
#define rs(s) scanf("%s",s)
#define gc getchar_unlocked
#define pc putchar_unlocked
#define mp make_pair
#define pb push_back 
#define lb lower_bound
#define ub upper_bound
#define endl "\n"
#define fast ios_base::sync_with_stdio(false);	cin.tie(NULL);	cout.tie(NULL);
using namespace std;
void in(int &x)
{
    register int c = gc(); x = 0; int neg = 0;
    for(;((c<48 || c>57) && c != '-');c = gc());if(c=='-') {neg=1;c=gc();} for(;c>47 && c<58;c = gc()) {x = (x<<1) + (x<<3) + c - 48;}
    if(neg) x=-x;
}
void out (int n) { int N = n, rev, count = 0;rev = N;  if (N == 0) { pc('0');  return ;}   while ((rev % 10) == 0) { count++; rev /= 10;}  rev = 0;while (N != 0) { rev = (rev<<3) + (rev<<1) + N % 10; N /= 10;}while (rev != 0) { pc(rev % 10 + '0'); rev /= 10;}
while (count--) pc('0');
}
ll parent[mx],arr[mx],node,edge;
vector<pair<ll,pair<ll,ll>>>v;
void initial()
{
	int i;
	rep(i,node+edge)
		parent[i] = i;
}
int root(int i)
{
	while(parent[i] != i)
	{
		parent[i] = parent[parent[i]];
		i = parent[i];
	}
	return i;
}
void join(int x,int y)
{
	int root_x = root(x);						//Disjoint set union by rank
	int root_y = root(y);
	parent[root_x] = root_y;
}
ll kruskal()
{
	ll mincost=0,i,x,y;
	rep(i,edge)
	{
		x = v[i].second.first;
		y = v[i].second.second;
		if(root(x) != root(y))
		{
			mincost += v[i].first;
			join(x,y);
		}
	}
	return mincost;
}
int main(){
	fast;
	while(1)
	{
		int i,j,from,to,cost,totalcost=0;
		cin>>node>>edge;					//Enter the nodes and edges
		if(node==0 && edge==0)	break;				//Enter 0 0 to break out
		initial();						//Initialise the parent array
		rep(i,edge)						
		{
			cin>>from>>to>>cost;				
			v.pb(mp(cost,mp(from,to)));
			totalcost += cost;
		}
		sort(v.begin(),v.end());
		// rep(i,v.size())
		// 	cout<<v[i].first<<"  ";
		cout<<kruskal()<<endl;
		v.clear();
	}
	return 0;
}