#include <iostream>
#include <algorithm>
#include <set>
#include <vector>
#include <map>
#include <fstream>
#include <set>
#include <cmath>
using namespace std;
char mat[2005][2500];
int main(){
    int n, m, k;
    cin >> n >> m >> k;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            cin >> mat[i][j];
        }
    }
    long long result = 0;
    for(int i = 0; i < n; i++) {
        int consecutive = 0;
        for(int j = 0; j < m; j++) {
            if(mat[i][j] == '.') {
                consecutive++;
            }
            if(mat[i][j] == '*' or j == m - 1) {
                result += max(0, consecutive - k + 1);
                consecutive = 0;
            }
        }
    }
    if(k != 1) {
    for(int i = 0; i < m; i++) {
        int consecutive = 0;
        for(int j = 0; j < n; j++) {
            if(mat[j][i] == '.') {
                consecutive++;
            }
            if(mat[j][i] == '*' or j == n - 1) {
                result += max(0, consecutive - k + 1);
                consecutive = 0;
            }
        }
    }
    }
    cout << result << endl;
    return 0;
}