#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int i,j,k,m,n,o,p,l,s,t,x,y,z,r,ll;
int dp[10001][501],ans[501],good[501];
int f[100001][4],q[100001],h[100001],bz[10001];
void insert(int x,int y,int z)
{ f[++t][1]=y,f[t][2]=q[x],f[t][3]=z,q[x]=t; }
int pd(int s)
{
for (int i=1;i<=ll;i++)
{
int gg=s&(1<<(i-1)),hh=s&(1<<(ll+i-1));
if ((!gg&&hh)||(!hh&&gg)) return 0;
}
return 1;
}
int main()
{
freopen("travel.in","r",stdin);
freopen("travel.out","w",stdout);
scanf("%d%d%d",&n,&m,&ll);
for (i=1;i<=m;i++) scanf("%d%d%d",&x,&y,&z),insert(x,y,z),insert(y,x,z);
int N=(1<<(2*ll))-1;
memset(dp,60,sizeof(dp));memset(good,60,sizeof(good));memset(ans,60,sizeof(ans));
for (i=1;i<=ll;i++)
dp[i][1<<(i-1)]=dp[n-i+1][1<<(ll+i-1)]=0;
for (s=1;s<=N;s++)
{
for (i=1;i<=n;i++)
{
for (t=1;t<=s;t++)
if ((t|s)==s)
{
for (k=q[i];k;k=f[k][2])
dp[i][s]=min(dp[i][s],dp[i][t]+dp[i][s-t]);
}
}
l=0,r=n;memset(bz,0,sizeof(bz));
for (j=1;j<=n;j++) h[j]=j,bz[j]=1;
while (l<r)
{
l++;
for (int k=q[h[l]];k;k=f[k][2])
{
if (dp[h[l]][s]+f[k][3]<dp[f[k][1]][s])
{
dp[f[k][1]][s]=dp[h[l]][s]+f[k][3];
if (!bz[f[k][1]]) bz[f[k][1]]=1,h[++r]=f[k][1];
}
}
bz[h[l]]=0;
}
for (i=1;i<=n;i++) good[s]=min(good[s],dp[i][s]);
}
ans[0]=0;
for (s=1;s<=N;s++)
{
if (s==N)
{
int gds=0;
}
for (t=0;t<s;t++)
if ((t|s)==s&&pd(s)) ans[s]=min(ans[s],ans[t]+good[s-t]);
}
if (ans[N]>1e9) ans[N]=-1;
printf("%d\n",ans[N]);
}