#include <bits/stdc++.h>
using namespace std;
const int N = 3000;
char a[N][N];
int n, m, k, vis[N][N];
long long ans = 0;
int main() {
  while (~scanf("%d%d%d", &n, &m, &k)) {
    ans = 0;
    for (register int i = 0; i <= n - 1; ++i) scanf("%s", a[i]);
    for (register int i = 0; i <= n - 1; ++i) {
      int c = 0;
      for (register int j = 0; j <= m - 1; ++j) {
        if (a[i][j] == '.')
          c++;
        else
          c = 0;
        if (c >= k) ans++;
      }
    }
    for (register int j = 0; j <= m - 1; ++j) {
      int c = 0;
      for (register int i = 0; i <= n - 1; ++i) {
        if (a[i][j] == '.')
          c++;
        else
          c = 0;
        if (c >= k) ans++;
      }
    }
    if (k == 1) ans /= 2;
    printf("%I64d\n", ans);
  }
  return 0;
}
