#include <iostream>
#include <cstdio>
using namespace std;
int n,m,k,ans,qx[10000001],qy[100000001],head,tail;
bool a[1001][1001];
const int dx[2]={1,0};
const int dy[2]={0,1};
int bfs(int i,int j)
{
    head=0;tail=1;
    qx[tail]=i;qy[tail]=1;a[i][j]=true;
    do{
        head++;
        int x,y;
        for(int k=0;k<2;k++)
        {
            x=qx[head]+dx[k];y=qy[head]+dy[k];
            if(x>0 && x<=n && y>0 && y<=m && !a[x][y])
            {
                tail++;
                qx[tail]=x; qy[tail]=y;
                a[x][y]=true;
            }
        }
    }while(head!=tail);
    return head;
}
int main()
{
    freopen("lake.in","r",stdin);
    freopen("lake.out","w",stdout);
    cin>>n>>m>>k;
    int x,y;
    for(int i=1;i<=k;i++)
    {   
        cin>>x>>y;
        a[x][y]=true;
    }
    
    for(int i=1;i<=n;i++)
    for(int j=1;j<=m;j++)
        if(!a[i][j]) ans=max(bfs(i,j),ans);
    
    cout<<ans*ans<<endl;
    return 0;
}