samac

//Nguyen Huu Hoang Minh
#include <bits/stdc++.h>
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define reset(x) memset(x, 0,sizeof(x))
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define N 105
#define remain(x) if (x > MOD) x -= MOD
#define ii pair<int, int>
#define iiii pair< ii , ii >
#define viiii vector< iiii >
#define vi vector<int>
#define vii vector< ii >
#define bit(x, i) (((x) >> (i)) & 1)
#define Task "test"
#define int long long

using namespace std;

typedef long double ld;
const int inf = 1e10;
const int minf = -1e10;

int t;
int n, m, c;
vector<ii> a[N];
int d[N];

void readfile()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    if (fopen(Task".inp","r"))
    {
        freopen(Task".inp","r",stdin);
        //freopen(Task".out","w",stdout);
    }
    cin >> t;
}


int ceil(int a, int b) {
    return b <= 0 ? inf : a / b + (a % b != 0);
}

void dijkstra()
{
    priority_queue<ii, vii, greater<ii>> q;
    for(int i=1; i<=n; i++) d[i] = inf;
    d[n] = 0;
    q.push(ii(0,n));
    while (q.size())
    {
        int u = q.top().se;
        int du =q.top().fi;
        q.pop();
        if (du != d[u]) continue;
        for(int i=0; i<a[u].size(); i++)
        {
            int v = a[u][i].fi;
            int uv = a[u][i].se;
            if (du + uv <= c && d[v] > du + uv)
            {
                d[v] = d[u] + uv;
                q.push(ii(d[v],v));
            }
            else{
                int k = ceil(du + uv - c, c - uv - uv);
                if (k != inf && (2*k+1)*uv + du < d[v])
                {
                    q.push(ii(d[v]=uv*(2*k+1)+du,v));
                }
            }
        }
    }
}

void solve()
{
    cin >> n >> m >> c;
    for(int i=1; i<=n; i++) a[i].clear();
    for(int i=1; i<=m; i++)
    {
        int u,v,z;
        cin >> u >> v >> z;
        a[u].pb(ii(v,z));
        a[v].pb(ii(u,z));
    }
    dijkstra();
    cout << d[1] << endl;
}

void proc()
{
    while (t--)
    {
        solve();
    }
}

signed main()
{
    readfile();
    proc();
    return 0;
}