Snake Rana

#include <bits/stdc++.h>
#define _xx ios_base::sync_with_sdtio(0);cin.tie(0);
#define INFS 0x3fffffff
#define INFB 0x3fffffffffffffff
#define printf pf
#define scanf sf
using namespace std;
typedef long long ll;
int orx[25][2];
int f, lm, rm, um, dm;
ll ans;
ll n, m, k;
void dfs(int i)
{

    if(i == k)
    {
        if(f == 0) return;
        ll cnt = lm*um*(n - dm + 1)*(m - rm + 1);
        ans = ans + (f%2 == 1 ? -cnt : cnt);
        return;
    }
    dfs(i + 1);
    int tlm = lm, trm = rm, tum = um, tdm = dm;
    lm = min(orx[i][1], lm);
    um = min(orx[i][0], um);
    rm = max(orx[i][1], rm);
    dm = max(orx[i][0], dm);
    f++;
    dfs(i + 1);
    lm = tlm;
    rm = trm;
    um = tum;
    dm = tdm;
    f--;
    return;
}
int main()
{
    int T;
    cin >> T;
    while(T--)
    {
        cin >> n >> m >> k;
        for(int i = 0; i < k; i++) cin >> orx[i][0] >> orx[i][1];
        f = 0;
        ans = n*(n + 1)*m*(m + 1)/4;
        lm = m;
        um = n;
        rm = 0;
        dm = 0;
        dfs(0);
        cout << ans << endl;

    }

    return 0;
}