#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;

#define REP(i,n) for(long long i = 0; i < (n); i++)
#define FOR(i, m, n) for(long long i = (m);i < (n); ++i)
#define ALL(obj) (obj).begin(),(obj).end()

template<class T> using V = vector<T>;
template<class T, class U> using P = pair<T, U>;

const ll MOD = (ll)1e9 + 7;
const ll MOD2 = 998244353;
const ll LLINF = (ll)1e18;
const ll INTINF = (ll)1e9;
const long double PI = 3.1415926535897932384626433;

template <class T> void corner(bool flg, T hoge) {if (flg) {cout << hoge << endl; exit(0);}}
template <class T, class U>ostream &operator<<(ostream &o, const map<T, U>&obj) {o << "{"; for (auto &x : obj) o << " {" << x.first << " : " << x.second << "}" << ","; o << " }"; return o;}
template <class T>ostream &operator<<(ostream &o, const set<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const multiset<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const vector<T>&obj) {o << "{"; for (int i = 0; i < (int)obj.size(); ++i)o << (i > 0 ? ", " : "") << obj[i]; o << "}"; return o;}
template <class T, class U>ostream &operator<<(ostream &o, const pair<T, U>&obj) {o << "{" << obj.first << ", " << obj.second << "}"; return o;}
template <template <class tmp>  class T, class U> ostream &operator<<(ostream &o, const T<U> &obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr)o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
void print(void) {cout << endl;}
template <class Head> void print(Head&& head) {cout << head;print();}
template <class Head, class... Tail> void print(Head&& head, Tail&&... tail) {cout << head << " ";print(forward<Tail>(tail)...);}
template <class T> void chmax(T& a, const T b){a=max<T>(a,b);}
template <class T> void chmin(T& a, const T b){a=min<T>(a,b);}
void YN(bool flg) {cout << ((flg) ? "YES" : "NO") << endl;}
void Yn(bool flg) {cout << ((flg) ? "Yes" : "No") << endl;}
void yn(bool flg) {cout << ((flg) ? "yes" : "no") << endl;}

int main() {
	int H,W,K; cin >> H >> W >> K;
	V<string> A(H);
	REP(i,H) cin >> A[i];
	int y,x;
	REP(i,H) REP(j,W) if(A[i][j] == 'S') y = i,x = j;

	V<V<int>> dist(H,V<int>(W,INTINF));
	dist[y][x] = 0;

	queue<P<int,int>> q;
	q.push({y,x});
	while(q.size()){
		int s = q.front().first;
		int t = q.front().second;
		q.pop();
		int d = dist[s][t];
		if(d == K) continue;

		if(0 < s && A[s-1][t] == '.' && dist[s-1][t] == INTINF){
			dist[s-1][t] = d + 1;
			q.push({s-1,t});
		}
		if(s < H - 1 && A[s+1][t] == '.' && dist[s+1][t] == INTINF){
			dist[s+1][t] = d + 1;
			q.push({s+1,t});
		}
		if(0 < t && A[s][t-1] == '.' && dist[s][t-1] == INTINF){
			dist[s][t-1] = d + 1;
			q.push({s,t-1});
		}
		if(t < W - 1 && A[s][t+1] == '.' && dist[s][t+1] == INTINF){
			dist[s][t+1] = d + 1;
			q.push({s,t+1});
		}
	}
	int ans = INTINF;
	REP(i,H) REP(j,W){
		if(dist[i][j] == INTINF) continue;
		int cnt;
		cnt = i/K + (i%K==0?0:1) + 1;
		chmin(ans,cnt);
		cnt = (W - 1 -j)/K + ((W - 1 -j)%K==0?0:1) + 1;
		chmin(ans,cnt);
		cnt = (H - 1 -i)/K + ((H - 1 -i)%K==0?0:1) + 1;
		chmin(ans,cnt);
		cnt = j/K + (j%K==0?0:1) + 1;
		chmin(ans,cnt);		
	}
	cout << ans << endl;
	return 0;
}


Measured memory_bytes: 3584