#include <bits/stdc++.h>

using namespace std;
using ll = long long;

#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
#define pb push_back
#define ff first
#define sc second

void solve() {
    int h, w, n; cin >> h >> w >> n;
    vector<pair<int, int>> a(n);
    for (int i = 0; i < n; i++) {a[i].first--; a[i].second--; cin >> a[i].first >> a[i].second; }
    int ans = 1e9;
    for (int up = 0; up < h; up++) {
        for (int down = 0; down < h; down++) {
            for (int left = 0; left < w; left++) {
                for (int right = 0; right < w; right++) {
                    vector<vector<int>> us(h, vector<int>(w));
                    for (int i = 0; i < n; i++) {
                        for (int j=-up;j<=down;j++){
                            for (int k = -left; k <= right; k++) {
                                if (a[i].first + j >= 0 && a[i].first + j < h && a[i].second + k >= 0 && a[i].second + k < w) us[a[i].first + j][a[i].second + k] = 1;
                            }
                        }
                    }
                    bool good = true;
                    for(int i=0;i<h;i++){
                        for(int j=0;j<w;j++){
                            if (!us[i][j]){
                                good = false;
                                break;
                            }
                        }
                    }
                    if(good)ans=min(ans,up+down+left+right);
                }
            }
        }
    }
    cout << ans << '\n';
}

signed main() {
    int tt = 1;
    #ifdef LOCAL 
        freopen("in.txt", "r", stdin);
        freopen("out.txt", "w", stdout);
        cin >> tt;
    #else
        ios::sync_with_stdio(false); 
        cin.tie(0); cout.tie(0);
    #endif

    while (tt--) {
        solve();
    }

    return 0;
}