#include <bits/stdc++.h>
using namespace std;
int pct(int x) { return __builtin_popcount(x); }
int pct(long long x) { return __builtin_popcountll(x); }
int bt(int x) { return 31 - __builtin_clz(x); }
int bt(long long x) { return 63 - __builtin_clzll(x); }
int cdiv(int a, int b) { return a / b + !(a < 0 || a % b == 0); }
long long cdiv(long long a, long long b) {
  return a / b + !(a < 0 || a % b == 0);
}
int nxt_C(int x) {
  int c = x & -x, r = x + c;
  return (((r ^ x) >> 2) / c) | r;
}
long long nxt_C(long long x) {
  long long c = x & -x, r = x + c;
  return (((r ^ x) >> 2) / c) | r;
}
vector<int> get_bits(int mask) {
  vector<int> bb;
  while (mask) {
    int b = bt(mask);
    bb.push_back(b);
    mask ^= (1 << b);
  }
  reverse(bb.begin(), bb.end());
  return bb;
}
int get_mask(vector<int> v) {
  int mask = 0;
  for (int x : v) {
    mask ^= (1 << x);
  }
  return mask;
}
template <typename T>
void uniq(vector<T> &v) {
  sort(v.begin(), v.end());
  v.resize(unique(v.begin(), v.end()) - v.begin());
}
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
long long rand(long long l, long long r) {
  uniform_int_distribution<long long> uid(l, r);
  return uid(rng);
}
void sc() {}
template <typename Head, typename... Tail>
void sc(Head &H, Tail &...T) {
  cin >> H;
  sc(T...);
}
const int mod = 1e9 + 7;
int pwr(int a, long long b) {
  int ans = 1;
  while (b) {
    if (b & 1) ans = (ans * 1LL * a) % mod;
    a = (a * 1LL * a) % mod;
    b >>= 1;
  }
  return ans;
}
const int N = 805;
char a[N][N];
int dist[N][N];
int dx[4] = {1, -1, 0, 0};
int dy[4] = {0, 0, 1, -1};
void solve() {
  int n, m, k;
  sc(n, m, k);
  pair<int, int> p;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      sc(a[i][j]);
      if (a[i][j] == 'S') p = {i, j};
      dist[i][j] = 1e9;
    }
  }
  dist[p.first][p.second] = 0;
  queue<pair<int, int> > q;
  q.push(p);
  while (!q.empty()) {
    pair<int, int> u = q.front();
    q.pop();
    if (dist[u.first][u.second] == k) {
      break;
    }
    for (int kk = 0; kk <= 3; kk++) {
      pair<int, int> v = {u.first + dx[kk], u.second + dy[kk]};
      if (v.first >= 1 && v.first <= n && v.second >= 1 && v.second <= m) {
        if (dist[v.first][v.second] > dist[u.first][u.second] + 1 &&
            a[v.first][v.second] != '#') {
          dist[v.first][v.second] = dist[u.first][u.second] + 1;
          q.push(v);
        }
      }
    }
  }
  int ans = 1e9;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= n; j++) {
      if (dist[i][j] <= k) {
        ans = min({ans, 1 + cdiv(min(n - i, i - 1), k),
                   1 + cdiv(min(m - j, j - 1), k)});
        if (i == 1 || i == n || j == 1 || j == m) ans = 1;
      }
    }
  }
  cout << ans;
}
int main() {
  ios ::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  for (int tt = 1; tt <= t; tt++) {
    solve();
  }
  return 0;
}
