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#include<iostream>
#include<vector>
using namespace std;


struct Address
{
  int x;
  int y;
};


vector<vector<bool>> FillTable(vector<vector<bool>> table, vector<Address> adds)
{
  for(int i=0;i<adds.size();i++)
  {
    table[adds[i].x][adds[i].y]=1;
  }
  return table;
}

vector<vector<bool>> FillEmptyTable(vector<vector<bool>> table, int n, int m)
{
  for(int i=0;i<=n+1;i++)
  {
    vector<bool> row;
    for(int j=0;j<=m+1;j++)
    {
      row.push_back(0);
    }
    table.push_back(row);
  }
  return table;
}

int CountPieces(vector<vector<bool>> table, int pieces, vector<Address> add)
{
  vector<vector<bool>> nextTable=table;
  vector<Address> nextAdds;
  bool changed = 0;
  for(int i=0;i<add.size();i++)
  {
    if(table[add[i].x][add[i].y]==1)
    {
      if((table[add[i].x-1][add[i].y]==0&&table[add[i].x+1][add[i].y]==0)||(table[add[i].x][add[i].y-1]==0&&table[add[i].x][add[i].y+1]==0))
      {
        nextTable[add[i].x][add[i].y]=0;
        pieces++;
        changed=1;
      }
      else nextAdds.push_back(add[i]);
    }
  }
  if(changed==0||nextAdds.size()==0) return pieces;
  else return(CountPieces(nextTable,pieces,nextAdds));
}

vector<Address> GetAddresses(int k)
{
  vector<Address> addresses;
  for(int i=0;i<k;i++)
  {
    Address add;
    cin>>add.x>>add.y;
    addresses.push_back(add);
  }
  return addresses;
}

vector<Address> removeAdd(vector<Address> adds, Address add)
{
  vector<Address> newAdd;
  for(int i=0;i<adds.size();i++)
  {
    if(adds[i].x!=add.x||adds[i].y!=add.y)
    {
      newAdd.push_back(adds[i]);
    }
  }
  return newAdd;
}

int main() 
{
  vector<vector<bool>> table;
  vector<Address> addresses;
  int n,m,k,q;
  cin>>n>>m>>k>>q;
  table=FillEmptyTable(table,n,m);
  addresses=GetAddresses(k);
  table=FillTable(table,addresses);
  cout<<CountPieces(table,0,addresses)<<endl;
  for(int i=0;i<q;i++)
  {
    int x,y;
    cin>>x>>y;
    if(table[x][y]==1)
    {
      table[x][y]=0;
      Address add;
      add.x=x;
      add.y=y;
      addresses=removeAdd(addresses,add);
    }
    else
    {
      table[x][y]=1;
      Address add;
      add.x=x;
      add.y=y;
      addresses.push_back(add);
    }
    cout<<CountPieces(table,0,addresses)<<endl;
  }
  
  return 0;
}