#include <bits/stdc++.h>
using namespace std;
using ll = long long;
unsigned euclidean_gcd(unsigned a, unsigned b) {
  if (a < b) return euclidean_gcd(b, a);
  unsigned r;
  while ((r = a % b)) {
    a = b;
    b = r;
  }
  return b;
}
ll ll_gcd(ll a, ll b) {
  if (a < b) return ll_gcd(b, a);
  ll r;
  while ((r = a % b)) {
    a = b;
    b = r;
  }
  return b;
}
class UnionFind {
 public:
  vector<ll> par;
  vector<ll> siz;
  UnionFind(ll sz_) : par(sz_), siz(sz_, 1LL) {
    for (ll i = 0; i < sz_; ++i) par[i] = i;
  }
  void init(ll sz_) {
    par.resize(sz_);
    siz.assign(sz_, 1LL);
    for (ll i = 0; i < sz_; ++i) par[i] = i;
  }
  ll root(ll x) {
    while (par[x] != x) {
      x = par[x] = par[par[x]];
    }
    return x;
  }
  bool merge(ll x, ll y) {
    x = root(x);
    y = root(y);
    if (x == y) return false;
    if (siz[x] < siz[y]) swap(x, y);
    siz[x] += siz[y];
    par[y] = x;
    return true;
  }
  bool issame(ll x, ll y) { return root(x) == root(y); }
  ll size(ll x) { return siz[root(x)]; }
};
long long modpow(long long a, long long n, long long mod) {
  long long res = 1;
  while (n > 0) {
    if (n & 1) res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}
long long modinv(long long a, long long mod) { return modpow(a, mod - 2, mod); }
void dfs(vector<string> &maze, ll nowi, ll nowj, ll &ans, ll &h, ll &w,
         vector<vector<bool>> &seen, ll kyori, ll k) {
  ans = min(ans, min(min(nowi, h - nowi - 1), min(nowj, w - nowj - 1)));
  seen[nowi][nowj] = true;
  if (kyori == k || ans == 0) return;
  if ((!(nowi + 1 >= h)) && maze[nowi + 1][nowj] == '.' &&
      seen[nowi + 1][nowj] == false)
    dfs(maze, nowi + 1, nowj, ans, h, w, seen, kyori + 1, k);
  if ((!(nowj + 1 >= w)) && maze[nowi][nowj + 1] == '.' &&
      seen[nowi][nowj + 1] == false)
    dfs(maze, nowi, nowj + 1, ans, h, w, seen, kyori + 1, k);
  if ((!(nowi - 1 < 0)) && maze[nowi - 1][nowj] == '.' &&
      seen[nowi - 1][nowj] == false)
    dfs(maze, nowi - 1, nowj, ans, h, w, seen, kyori + 1, k);
  if ((!(nowj - 1 < 0)) && maze[nowi][nowj - 1] == '.' &&
      seen[nowi][nowj - 1] == false)
    dfs(maze, nowi, nowj - 1, ans, h, w, seen, kyori + 1, k);
  return;
}
int main() {
  ll h, w, k;
  cin >> h >> w >> k;
  vector<string> z(h);
  for (int i = 0; i < h; i++) {
    cin >> z[i];
  }
  ll sih = 0;
  ll sjw = 0;
  for (int i = 0; i < h; i++) {
    for (int j = 0; j < w; j++) {
      if (z[i][j] == 'S') {
        sih = i;
        sjw = j;
      }
    }
  }
  vector<vector<bool>> zz(h, vector<bool>(w, false));
  ll ans = 13413434127912;
  dfs(z, sih, sjw, ans, h, w, zz, 0, k);
  cout << (ans + k - 1) / k + 1 << endl;
}
