/**
* Created by Frans on 5.10.2015.
*/
public class Tontti{
static int height;
static int width;
static int[][] kentta;
static int treeWanted;
static int trees;
public static void main(String[] args){
IO io = new IO();
height = io.nextInt();
width = io.nextInt();
treeWanted = io.nextInt();
trees = 0;
kentta = new int[width][height];
//calculate trees and save it in to array
for (int y=0; y<height; y++) {
String line = io.next();
for (int x=0; x<width; x++){
if (line.charAt(x) == '*'){
kentta[x][y] = 1;
trees ++;
}else{
kentta[x][y] = 0;
}
}
}
//optimized test area
double density = (double) trees/ (double) (width*height);
int optimizeW = Math.max((int) Math.ceil(Math.pow((treeWanted / density), 0.5)), 2);
int foundArea = 0;
int direction =0;
//-1, koska oikea reuna turha kayda
for(int y=0; y<height-1; y++){
for (int x=0; x<width-1; x++){
int testW = optimizeW;
testW = Math.min(Math.min(testW, height-y), width-x);
int amount = CountTree(testW, x,y);
//haluttu määrä
if (amount == treeWanted){
foundArea ++;
foundArea += IncreaseArea(testW, x, y);
foundArea += DecreaseArea(testW, x, y);
} else if (amount < treeWanted){
foundArea += IncreaseArea(testW, x, y);
} else { //amount > treeWanted
foundArea += DecreaseArea(testW, x, y);
}
}
}
io.println(foundArea);
io.close();
}
private static int CountTree(int testW, int x, int y) {
int squareTreeAmount = 0;
for (int y2 = y; y2 < y + testW; y2++) {
for (int x2 = x; x2 < x + testW; x2++) {
squareTreeAmount += kentta[x2][y2];
}
}
return squareTreeAmount;
}
private static int DecreaseArea(int testW, int x, int y){
int foundArea = 0;
testW --;
while(testW >= 2){
int squareTreeAmount = CountTree(testW, x, y);
if(squareTreeAmount == treeWanted){
foundArea ++;
}
testW --;
}
return foundArea;
}
private static int IncreaseArea(int testW, int x, int y){
int foundArea = 0;
testW ++;
while(testW + y < height && testW + x < width){
int squareTreeAmount = CountTree(testW, x, y);
if(squareTreeAmount == treeWanted){
foundArea ++;
}
testW ++;
}
return foundArea;
}
}