#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair< ll, ll > pii;
const ll MAX = 1024;
const ll INF = 0x3f3f3f3f;
vector< pii > G[MAX];
ll d[MAX];
void dijkstra(ll start)
{
    ll u, v, i, c, w;
    priority_queue< pii, vector< pii >, greater< pii > > Q;
    memset(d, INF, sizeof d);
    Q.push(pii(0, start));
    d[start] = 0;
    while(!Q.empty())
    {
        u = Q.top().second;
        Q.pop();
        for(i = 0; i < G[u].size(); i++)
        {
            w = G[u][i].first;
            v = G[u][i].second;
            if(d[v] > max(d[u],w))
            {
                d[v] = min(d[v],max(w,d[u]));
                Q.push(pii(d[v], v));
            }
        }
    }
}

int main()
{
    ll n, e, i, u, v, w, start,t,cas=1;
    scanf("%lld",&t);
    while(t--)
    {
        scanf("%lld %lld", &n, &e);
        for(i = 0; i <= n; i++)
            G[i].clear();
        for(i = 0; i < e; i++)
        {
            scanf("%lld %lld %lld", &u, &v, &w);
            G[u].push_back(pii(w, v));
            G[v].push_back(pii(w, u));
        }
        scanf("%lld",&start);
        dijkstra(start);
        printf("Case %lld:\n", cas++);
        for(int i=0; i<n; i++)
        {
            if(d[i] >= INF)
                printf("Impossible\n");
            else
                printf("%lld\n",d[i]);
        }
    }
}