#include<bits/stdc++.h>
#define ios ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)
using namespace std;using ll = long long;using PLL = pair<ll,ll>;
const ll MAX = 1e18;const ll MIN = -1e18;const ll INF=0x3f3f3f3f;
const ll Q = 2e5+9;const ll MOD = 1e9 + 7;
// vector<vector<ll>> a;
bool cmp(PLL a,PLL b){
    if(a.first==b.first) return a.second<b.second;
    return a.first<b.first;
}
map<ll,pair<ll,ll>> mp;
bool check(ll x){
    vector<PLL> v;
    for (ll i = 0; i <= x; i++)
    {
        v.push_back({mp[i].first,mp[i].second});
    }
    sort(v.begin(),v.end(),cmp);
    ll now=v[0].second;
    for (ll i = 1; i < x; i++)
    {
        if(v[i].second<now) return false;
        now=v[i].second;
    }
    return true;
}

void solve(){
    mp.clear();
   ll n,m;cin>>n>>m;
    // a.resize(n+10);

    // for (ll i = 0; i <= n; i++)
    // {
    //     a[i].resize(m+10);
    // }
    ll a[n+10][m+10];
   for (ll i = 1; i <= n; i++)
   {
    for (ll j = 1; j <= m; j++)
    {
        cin>>a[i][j];
        mp[a[i][j]]={i,j};
    }
   }
   ll l=0,r=(n*m)-1;ll ans=0;
    while(l<=r){
        ll mid=(l+r)>>1;
        if(check(mid)){
            ans=mid;
            l=mid+1;
        }else{
            r=mid-1;
        }
    }
    cout<<ans+1<<"\n";
}
int main(){
    ios;ll _=1;cin>>_;
    while (_--)solve();
    return 0;
}