//异或运算：相同为假，不同为真

#include<cstdio>

#include<algorithm>

#define maxn 105

using namespace std;

int n,m,sum,flag;

int fa[maxn];

struct Edge

{

    int u,v,w;

    bool operator<(const Edge &cmp)const{

        return w<cmp.w;

    }

}edge[maxn*maxn>>];

int Findset(int x)

{

    if(fa[x]==x) return fa[x]=x;

    else return fa[x]=Findset(fa[x]);

}

int main()

{

    while(scanf("%d",&n),n){

        m=(n-)*n/;

        for(int i=;i<=n;i++)

            fa[i]=i;

        for(int i=;i<m;i++){

            scanf("%d%d%d%d",&edge[i].u,&edge[i].v,&edge[i].w,&flag);

            if(flag)

                fa[edge[i].u]=edge[i].v;

        }

        sort(edge,edge+m);

        sum=;

        for(int i=;i<m;i++){

            int x=Findset(edge[i].u);

            int y=Findset(edge[i].v);

            if(x!=y){

                fa[x]=y;

                sum+=edge[i].w;

            }

        }

        printf("%d\n",sum);

    }

} 

#include<cstdio>

#include<cstring>

#define INF 0x3f3f3f3f

#define maxn 105

int i,j,k,n,m,min,sum;

int lowcost[maxn],visit[maxn];

int graph[maxn][maxn];

void Prim()

{

    sum=;

    memset(visit,,sizeof(visit));

    visit[]=;

    for(i=;i<=n;i++)

        lowcost[i]=graph[][i];

    for(i=;i<=n;i++){

        min=INF;

        for(j=;j<=n;j++){

            if(!visit[j]&&min>lowcost[j]){

                min=lowcost[j];

                k=j;

            }

        }

        sum+=lowcost[k];

        visit[k]=;

        for(j=;j<=n;j++){

            if(!visit[j]&&lowcost[j]>graph[k][j])

                lowcost[j]=graph[k][j];

        }

    }

}

int main()

{

    int a,b,c,d;

    while(scanf("%d",&n),n){

        m=(n-)*n/;

        memset(graph,INF,sizeof(graph));

        while(m--){

            scanf("%d%d%d%d",&a,&b,&c,&d);

            if(d) graph[a][b]=graph[b][a]=;

            else graph[a][b]=graph[b][a]=c;

        }

        Prim();

        printf("%d\n",sum);

    }

    return ;

}