#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
#include<queue>
#include<map>
#include<vector>
using namespace std;
#define ll __int64
#define inf 99999999
int n,m;
int du[100010];
int flag[100010];
int ans[100010];
void init()
{
    memset(du,0,sizeof(flag));
    memset(flag,0,sizeof(flag));
}
int main() {
    int x,y,z,i,t;
    int T;
    scanf("%d",&T);
    while(T--)
    {
        init();
        vector<int>v[100010];
        priority_queue<int>q;
        scanf("%d%d",&n,&m);
        for(i=0;i<m;i++)
        {
            int u,vv;
            scanf("%d%d",&u,&vv);
            v[u].push_back(vv);
            du[vv]++;
        }
        int ji=0;
        for(i=1;i<=n;i++)
        if(du[i]==0)
        q.push(i),flag[i]=1;
        while(!q.empty())
        {
            int gg=q.top();
            q.pop();
            ans[ji++]=gg;
            for(i=0;i<v[gg].size();i++)
            {
                int vv=v[gg][i];
                du[vv]--;
                if(du[vv]==0&&!flag[vv])
                q.push(vv),flag[vv]=1;
            }
        }
        int minn=inf;
        ll getans=0;
        for(i=0;i<ji;i++)
        minn=min(minn,ans[i]),getans+=minn;
        printf("%I64d\n",getans);

    }
    return 0;
}