#include <bits/stdc++.h>
using namespace std;
const long long INFL = 1LL << 60;
const int INF = 1 << 30;
long long MOD = 1000000007;
vector<long long> dy = {1, -1, 0, 0, 0};
vector<long long> dx = {0, 0, 1, -1, 0};
long long max(long long a, long long b) { return (a > b) ? a : b; }
long long min(long long a, long long b) { return (a < b) ? a : b; }
long long pow_long(long long x, long long k) {
  long long res = 1;
  while (k > 0) {
    if (k % 2) res *= x;
    x *= x;
    k /= 2;
  }
  return res;
}
long long pow_mod(long long x, long long k) {
  x %= MOD;
  x += MOD;
  x %= MOD;
  long long res = 1;
  while (k > 0) {
    if (k % 2) {
      res *= x;
      res %= MOD;
    }
    x *= x;
    x %= MOD;
    k /= 2;
  }
  return res;
}
long long inverse(long long x) { return pow_mod(x, MOD - 2); };
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long lcm(long long x, long long y) { return x / gcd(x, y) * y; };
long long kai_mod(long long x) {
  if (x == 0) return 1;
  return x * kai_mod(x - 1) % MOD;
}
const int MAXcomb = 200010;
long long fac[MAXcomb], finv[MAXcomb], inv[MAXcomb];
void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (int i = 2; i < MAXcomb; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}
long long comb(int n, int k) {
  if (n < k) return 0;
  if (n < 0 || k < 0) return 0;
  return fac[n] * finv[k] % MOD * finv[n - k] % MOD;
}
int H, W, K;
vector<vector<char>> mp(810, vector<char>(810));
int sy, sx;
vector<vector<vector<int>>> dist(810,
                                 vector<vector<int>>(810,
                                                     vector<int>(1200, INF)));
int dijkstra() {
  priority_queue<pair<pair<int, int>, pair<int, int>>,
                 vector<pair<pair<int, int>, pair<int, int>>>,
                 greater<pair<pair<int, int>, pair<int, int>>>>
      pque;
  dist[sy][sx][0] = 0;
  pque.push({{0, 0}, {sy, sx}});
  while (!pque.empty()) {
    pair<pair<int, int>, pair<int, int>> p = pque.top();
    pque.pop();
    if (p.second.first == 0 || p.second.first == H - 1) {
      return (p.first.first - 1) / K + 1;
    }
    if (p.second.second == 0 || p.second.second == W - 1) {
      return (p.first.first - 1) / K + 1;
    }
    if ((p.first.first / K + 1) * K <
        dist[p.second.first][p.second.second][p.first.second + K]) {
      dist[p.second.first][p.second.second][p.first.second + K] =
          (p.first.first / K + 1) * K;
      pque.push({{dist[p.second.first][p.second.second][p.first.second + K],
                  p.first.second + K},
                 {p.second.first, p.second.second}});
    }
    if (dist[p.second.first][p.second.second][p.first.second] < p.first.first)
      continue;
    for (long long i = 0; i < (5); i++) {
      int ny = p.second.first + dy[i];
      int nx = p.second.second + dx[i];
      if (mp[ny][nx] == '.') {
        if (p.first.first + 1 < dist[ny][nx][p.first.second]) {
          dist[ny][nx][p.first.second] = p.first.first + 1;
          pque.push({{dist[ny][nx][p.first.second], p.first.second}, {ny, nx}});
        }
      } else {
        if (p.first.second == 0) continue;
        if (p.first.first + 1 < dist[ny][nx][p.first.second - 1]) {
          dist[ny][nx][p.first.second - 1] = p.first.first + 1;
          pque.push({{dist[ny][nx][p.first.second - 1], p.first.second - 1},
                     {ny, nx}});
        }
      }
    }
  }
}
int main() {
  cin >> H >> W >> K;
  K = min(K, 410);
  for (long long i = 0; i < (H); i++) {
    for (long long j = 0; j < (W); j++) {
      cin >> mp[i][j];
      if (mp[i][j] == 'S') {
        sy = i;
        sx = j;
        mp[i][j] = '.';
      }
    }
  }
  cout << dijkstra() << endl;
}
