#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define EPS 1e-7
#define INF 2000000000
const int MODN = 1e9 + 7;
#define rep(i, n) for (int i = 0, _n = (int)(n); i < _n; i++)
typedef long long ll;
typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;

int main(){
    int T; scanf("%d",&T);
    vector<vii> adjlist;
    while(T--){
        int v,e; scanf("%d %d",&v,&e);
        adjlist.clear();
        adjlist.resize(v+2,vii());
        while(e--){
            int f,t,w; scanf("%d %d %d",&f,&t,&w);
            adjlist[f].pb(ii(t,w));
        }
        int a,b; scanf("%d %d",&a,&b);
        vi dist(v+2, INF); dist[a]=0;
        priority_queue<ii, vector<ii>, greater<ii> >pq; pq.push(ii(0,a));
        while(!pq.empty()){
            int u=pq.top().se;
            int d=pq.top().fi;
            pq.pop();
            if(d>dist[u]) continue;
            for(ii front:adjlist[u]){
                if(dist[u]+front.se<dist[front.fi]){
                    dist[front.fi]=dist[u]+front.se;
                    pq.push(ii(dist[front.fi],front.fi));
                }
            }
        }
        if(dist[b]==INF) printf("NO\n");
        else printf("%d\n", dist[b]);
    }
    return 0;
}
/*

5
3 1 9 2 7

*/