3
1 2 1
1 3 2
2 3 4
4
1 2 1
1 3 4
1 4 1
2 3 3
2 4 2
3 4 5
0

3
5

Hint
Hint
 
Huge input, scanf is recommended.

#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
#define maxn 100001
int father[maxn];
int flag;
void init()
{
    for(int i=0;i<maxn;i++)
        father[i]=i;
}
int Find(int x)
{
    return x==father[x]?x:father[x]=Find(father[x]);
}
void Union(int x,int y)
{
    int fx=Find(x);
    int fy=Find(y);
    if(fx==fy)
    {
        flag=0;
    }
    else
    {
        father[fy]=fx;
        flag=1;
    }
}
struct city
{
    int a,b,c;
};
int cmp(city x,city y)
{
    return x.c<y.c;
}
int main()
{
    int m,n,q;
    struct city h[10001];
    while(cin>>m)
    {
        if(!m)  break;
        q=0;
        init();
        n=m*(m-1)/2;
        for(int i=0;i<n;i++)
        {
            cin>>h[i].a>>h[i].b>>h[i].c;
        }
        sort(h,h+n,cmp);
        for(int i=0;i<n;i++)
        {
                Union(h[i].a,h[i].b);
                if(flag)
                    q+=h[i].c;
        }
        cout<<q<<endl;
    }
    return 0;
}