int initial_binser(int a[],int x,int p,int q,int min,int n)
{
int pos;
if(a[0]<=x)
pos=binser(a,1,min,x);
else
pos=binser(a,min+1,n,x);
return pos;
}
int binser(int a[],int p,int q,int x)
{
int mid;
if(p > q)
return -1;
mid = (p+q)/2;
if(x==a[mid])
return mid;
else
{
if(x <= a[mid])
binser(a,p,mid-1,x);
else
binser(a,mid+1,q,x);
}
}
int main()
{
long i,j,sum,a,b,c,M;
char s1[1000],s2[1000],str[1000];
while(scanf("%ld %ld",&N,&M)==2&&(N||M))
{
getchar();
make_set();
for(i=0;i<N;i++)
gets(name[i]);
qsort(name,N,sizeof(name[0]),cmp);
for(i=0;i<M;i++)
{
gets(str);
sscanf(str,"%s %s %ld",s1,s2,&c);
a=binser(s1);
b=binser(s2);
P[i].u=a;P[i].v=b;P[i].cost=c;
}
gets(str);
qsort(P,M,sizeof(S),cmp1);
j=0;sum=0;
for(i=0;j<N-1&&i<M;i++)
{
a=find(P[i].u); b=find(P[i].v);
if(a!=b)
{
j++;
sum+=P[i].cost;
link(a,b);
}
}
if(j!=N-1)
printf("Impossible\n");
else
printf("%ld\n",sum);
}
return 0;
}
