#include <bits/stdc++.h>
#define ll long long int
#define vi vector<ll>
using namespace std;

int main() {
    int t;
    cin>>t;
    while(t--){
        ll n,m,k;
        cin>>n>>m>>k;
        if(k==0){
            ll ans=n+m-2;
            cout<<ans<<endl;
            continue;
        }
        vector<vector<ll>> v(k,vector<ll>(2));
        for(ll i=0;i<k;i++) cin>>v[i][0]>>v[i][1];
        sort(v.begin(),v.end());
        // for(auto i:v){
        //     cout<<i[1]<<" ";
        // }
        // cout<<endl;
        vector<vi> arr;
        for(ll i=0;i<k;i++){
            if(v[i][0]!=n && v[i][1]!=m){
                arr.push_back(v[i]);
            }
        }
        // for(auto i:arr){
        //     cout<<i[0]<<" "<<i[1]<<endl;
        // }
        ll l=arr.size();
        vector<ll> dp(l+1,LLONG_MAX);
        dp[0]=0;
        ll res=0;
        for(ll i=0;i<l;){
            ll z1=i;
            vector<vi> temp;
            while(i<l && arr[i][0]==arr[z1][0]){
                ll idx=upper_bound(dp.begin(),dp.end(),arr[i][1])-dp.begin();
                if(idx!=l+1 && dp[idx-1]<arr[i][1]){
                    temp.push_back({idx,arr[i][1]});
                    res=max(res,idx);
                }
                i++;
            }

            for(auto j:temp){
                // cout<<j[0]<<" "<<j[1]<<endl;
                dp[j[0]]=min(dp[j[0]],j[1]);
            }
        }
        ll ans=n+m-2-res;
        cout<<ans<<endl;
    }
}