#include <iostream>
#include<bits/stdc++.h>
#include<cmath>
typedef long long ll ;
const ll inf = 1e9 + 7 ;

using namespace std;

int maxtav(vector<vector<int> > &d , int n)
{
    int ans = 0 ;
    for(int i = 1 ; i <= n ; i++)
        for(int j = 1 ; j <= n ; j++)
            ans = max(ans , d[i][j]) ;
    return ans ;
}

int main()
{
    int n , m , k ;
    cin >> n >> m >> k ;

    vector<vector<int> > d(201 , vector<int>(201 , inf)) ;
    for (int i = 1; i <= n * m; i++) {
    for (int j = 1; j <= n * m; j++) {
        if (i == j) {
            d[i][j] = 0;
        } else {
            d[i][j] = abs((i - 1) / m - (j - 1) / m) + abs((i - 1) % m - (j - 1) % m);
        }
    }
}


    while(k--)
    {
        int u , v ;
        cin >> u >> v ;

        if(u != v)
        {
            d[u][v] = 1 ;
            d[v][u] = 1 ;
        }

    for(int i = 1 ; i <= n * m ; i++)
    {
        for(int j = 1 ; j <= n * m ; j++)
        {
            d[i][j] = min(d[i][j] ,
                          d[i][u] + 1 + d[v][j] ) ;
            d[i][j] = min(d[i][j] ,
                          d[i][v] + 1 + d[u][j] ) ;

            d[j][i] = min(d[j][i] ,
                          d[j][u] + 1 + d[v][i] ) ;
            d[j][i] = min(d[j][i] ,
                          d[j][v] + 1 + d[u][i] ) ;
        }
    }

    cout << maxtav(d , n * m) << "\n" ;


    }



    return 0;
}