int@n,@m,@k,@r--[k],a[m],b[],c[];
rd((a--,b--,c)(m));

wgraph<int>g;
g.setEdge(n,m,a,b,c);

int d[2k+2][2k];
int e[m];
rep(i,2k+2){
	g.getDist(i<2k?i&1?b[r[i/2]]:a[r[i/2]]:i==2k?0:n-1,e);
	rep(j,2k){
		d[i][j]=e[j&1?b[r[j/2]]:a[r[j/2]]];
	}
}

int f[1<<k][2k];
rep(i,1<<k){
	rep(j,2k){
		if(i&1<<j/2){
			int l=int_inf;
			if(int q=i^1<<j/2){
				rep(o,2k){
					if(q&1<<o/2){
						l<?=f[q][o]+d[o][j];
					}
				}
			}else{
				l=d[2k][j];
			}
			f[i][j^1]=l+c[r[j/2]];
		}
	}
}

wt(min[int][i,0,2k](f[(1<<k)-1][i]+d[2k+1][i]));