/*最小费用最大流*/
#include<iostream>
#include<cstring>
#include<cstring>
#include<cmath>
#include<cstdio>
using namespace std;
const int Maxn = 1010;
const int inf = 1000010;
struct Edge{int v;int val;int cost;int next;
}edge[Maxn*100];
int head[Maxn],n,g[Maxn][Maxn],m,k;
int e;
int pre[Maxn], pos[Maxn];
int dis[Maxn], que[Maxn*100];
bool vis[Maxn];
void add(int u, int v, int val, int cost)
{edge[e].v = v;edge[e].val = val;edge[e].cost = cost;edge[e].next = head[u];head[u] = e++;edge[e].v = u;edge[e].val = 0;edge[e].cost = -cost;edge[e].next = head[v];head[v] = e++;
}
void init()
{memset(head,-1,sizeof(head));for(int i=0;i<Maxn;i++)for(int j=0;j<Maxn;j++)g[i][j]=inf;e=0;
}
bool spfa(int s, int t)
{int i;memset(pre, -1, sizeof(pre));memset(vis, 0, sizeof(vis));int Head, tail;Head = tail = 0;for(i = 0; i < Maxn; i++)dis[i] = inf;que[tail++] = s;pre[s] = s;dis[s] = 0;vis[s] = 1;while(Head != tail){int now = que[Head++];vis[now] = 0;for(i=head[now]; i != -1; i = edge[i].next){int adj = edge[i].v;//cout<<now<<" "<<adj<<" "<<dis[now]<<" "<<edge[i].cost<<" "<<dis[adj]<<" "<<edge[i].val<<endl;if(edge[i].val > 0 && dis[now] + edge[i].cost < dis[adj]){dis[adj] = dis[now] + edge[i].cost;pre[adj] = now;pos[adj] = i;if(!vis[adj]){vis[adj] = 1;que[tail++] = adj;}}}}return pre[t] != -1;
}
int MinCostFlow(int s, int t, int flow)
{int i;int cost = 0;flow = 0;while(spfa(s, t)){int f = inf;for(i = t; i != s; i = pre[i])if (edge[pos[i]].val < f)f = edge[pos[i]].val;flow += f;cost += dis[t] * f;for(i = t; i != s; i = pre[i]){edge[pos[i]].val -= f;edge[pos[i] ^ 1].val += f;}// cout<<cost<<endl;
    }return cost;// flow是最大流值
}
void floyd()
{int i,j,k;for(k=0;k<=n;k++)for(i=0;i<=n;i++)for(j=0;j<=n;j++){if(g[k][j]==inf) continue;g[i][j]=min(g[i][j],g[i][k]+g[k][j]);}
}
void build(int lim)
{memset(head,-1,sizeof(head));e=0;int ss = 0;int s = 2*n+1;int t = 2*n+2;add(s,ss,lim,0);for(int i=1;i<=n;i++){if(g[0][i] < inf){add(ss,i,1,g[0][i]);add(i+n,t,1,g[i][0]);}add(i,i+n,1,-inf);for(int j=i+1;j<=n;j++){if(g[i][j] < inf){add(i+n,j,1,g[i][j]);}}}add(ss,t,k,0);return;
}
int solve()
{int i,j;int ans;ans=inf;build(k);ans=min(ans,MinCostFlow(n+n+1,n+n+2,0)+n*inf);return ans;
}
int main()
{int i,j,u,v,c;while(scanf("%d%d%d",&n,&m,&k)!=EOF,n||m||k){init();for(i=1;i<=m;i++){scanf("%d%d%d",&u,&v,&c);if(g[u][v]>c)g[u][v]=g[v][u]=c;}floyd();printf("%d\n",solve());}return 0;
}