#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <string>
#include <algorithm>
#include <iostream>
using namespace std;
#define ll long long
#include <queue>

const double eps=1e-8;
const ll inf=1e9;
const ll mod=998244353;
const int maxn=1e3+10;

struct node
{
    int d;
    ll len;
    node *to;
}*e[maxn];

struct rec
{
    int d,maxd;
    ll dist;
    bool operator<(const rec &y) const
    {
        return dist>y.dist;
    }
};

priority_queue<rec,vector<rec> > st;

ll dist[maxn];
int maxp[maxn];

int main()
{
    node *p;
    int t,n,m,u,v,i,j,be,dd;
    ll sum,w;
    scanf("%d",&t);
    while (t--)
    {
        scanf("%d%d",&n,&m);
        for (i=1;i<=n;i++)
            e[i]=0;
        while (m--)
        {
            scanf("%d%d%I64d",&u,&v,&w);
            p=new node();
            p->d=v;
            p->len=w;
            p->to=e[u];
            e[u]=p;

            p=new node();
            p->d=u;
            p->len=w;
            p->to=e[v];
            e[v]=p;
        }
        sum=0;
        for (be=1;be<=n;be++)
        {
            memset(dist,0x7f,sizeof(dist));
            dist[be]=0;
            memset(maxp,0,sizeof(maxp));

            while (!st.empty())
                st.pop();

            st.push({be,0,0});
            while (!st.empty())
            {
                u=st.top().d;
                v=st.top().maxd;
                w=st.top().dist;
                st.pop();
                if (w!=dist[u] || v!=maxp[u])
                    continue;
                if (u!=be)
                    v=max(v,u);

                p=e[u];
                while (p)
                {
                    dd=p->d;
                    if (dist[dd]>w+p->len || (dist[dd]==w+p->len && maxp[dd]>v))
                    {
                        dist[dd]=w+p->len;
                        maxp[dd]=v;
                        st.push({dd,v,dist[dd]});
                    }
                    p=p->to;
                }
            }

            for (i=1;i<=n;i++)
                sum+=maxp[i];
        }
        printf("%I64d\n",sum%mod);
    }
    return 0;
}
/*
2
4 2
1 2 3
2 3 4

4 4
1 2 1
2 3 1
3 4 1
4 1 1
*/