847I

#include <iostream>
#include <queue>
#include <algorithm>
using namespace std;

int n, m, q, p;
int bfs_tab[253][253];
char t[253][253];
int sum[253][253];

//pair <int, int> qq;
queue < pair<int, int> > Q;

const int d_x[4] = {-1, 0, 1, 0};
const int d_y[4] = {0, 1, 0, -1};


int pow2 (int y)
{
    int w = 1;
    for (int i = 0; i < y; i++)
        w*=2;

        return w;
}

void bfs(int a, int b);

int main (){

cin >> n >> m >> q >> p;

for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++)
       cin >> t[i][j];

for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++)
    {
        if (t[i][j] >= 'A' && t[i][j] <= 'Z')
        {
            bfs(i, j);

        /*  for (int i = 0; i < n; i++)
            {
                for (int j = 0; j < m; j++)
                        cout << bfs_tab[i][j] << " ";
                        cout << endl;
            }
                cout << endl;*/
        }

    }


int sol=0;


for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++)
        if (sum[i][j]>p)
            sol++;


            cout << sol;



return 0;



}


void bfs(int a, int b)
{
    while (!Q.empty())
        Q.pop();

     for (int i2 = 0; i2 < n; i2++)
        for (int j2 = 0; j2 < m; j2++)
            bfs_tab[i2][j2]=0;

    //bool pot = false;
    //qq=make_pair(a, b);
    int value=q*(t[a][b]-64);
    bfs_tab[a][b]=1;
    sum[a][b]+=value;

    for (Q.push(make_pair(a, b)); !Q.empty(); Q.pop())
    {
        pair <int, int> qq = Q.front();

        if (value/pow2(bfs_tab[qq.first][qq.second])==0)
            break;

        for (int k = 0; k < 4; k++)
        {
            int a1=qq.first+d_x[k];
            int b1=qq.second+d_y[k];

            if (a1 < n && a1 >= 0 && b1 < m && b1 >= 0 && bfs_tab[a1][b1]==0 && t[a1][b1]!='*')
            {
                bfs_tab[a1][b1]=bfs_tab[qq.first][qq.second]+1;
                sum[a1][b1]+=value/pow2(bfs_tab[qq.first][qq.second]);

                Q.push(make_pair(a1, b1));
            }
        }

    }

}