#include <bits/stdc++.h>
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("O3")
#pragma GCC target("sse4,avx2,fma,avx")
#define FOR(i, x, y) for (int i = x; i < y; i++)
typedef long long ll;
using namespace std;
bool open[1002][1002];
int n, m, visited[1002][1002], to_wall[1002][1002];
vector<pair<int, pair<int, int>>> graph[1002][1002];
pair<int, int> src, dest;
inline bool has_wall(int x, int y) {
return !(open[x - 1][y] && open[x + 1][y] && open[x][y - 1] && open[x][y + 1]);
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m;
FOR(i, 1, n + 1) FOR(j, 1, m + 1) {
char c;
cin >> c;
if (c != '#') open[i][j] = true;
if (c == 'S') src = {i, j};
if (c == 'C') dest = {i, j};
}
FOR(i, 1, n + 1) FOR(j, 1, m + 1) {
if (open[i - 1][j]) graph[i][j].push_back({1, {i - 1, j}});
if (open[i + 1][j]) graph[i][j].push_back({1, {i + 1, j}});
if (open[i][j - 1]) graph[i][j].push_back({1, {i, j - 1}});
if (open[i][j + 1]) graph[i][j].push_back({1, {i, j + 1}});
}
queue<pair<int, int>> q;
FOR(i, 0, n + 2) FOR(j, 0, m + 2) {
if (open[i][j] && has_wall(i, j)) {
to_wall[i][j] = 1;
q.push({i, j});
}
}
while (q.size()) {
pair<int, int> curr = q.front();
q.pop();
for (pair<int, pair<int, int>> i : graph[curr.first][curr.second]) {
if (!to_wall[i.second.first][i.second.second]) {
to_wall[i.second.first][i.second.second] = to_wall[curr.first][curr.second] + 1;
q.push(i.second);
}
}
}
pair<int, int> bound;
bool has;
FOR(i, 0, n + 1) FOR(j, 0, m + 1) {
if (!open[i][j]) has = false;
else {
if (!has) bound = {i, j};
else graph[i][j].push_back({to_wall[i][j], bound});
has = true;
}
}
FOR(j, 0, m + 1) FOR(i, 0, n + 1) {
if (!open[i][j]) has = false;
else {
if (!has) bound = {i, j};
else graph[i][j].push_back({to_wall[i][j], bound});
has = true;
}
}
for (int i = n + 1; i; i--) for (int j = m + 1; j; j--) {
if (!open[i][j]) has = false;
else {
if (!has) bound = {i, j};
else graph[i][j].push_back({to_wall[i][j], bound});
has = true;
}
}
for (int j = m + 1; j; j--) for (int i = n + 1; i; i--) {
if (!open[i][j]) has = false;
else {
if (!has) bound = {i, j};
else graph[i][j].push_back({to_wall[i][j], bound});
has = true;
}
}
priority_queue<pair<int, pair<int, int>>> pq;
pq.push({-1, src});
while (pq.size()) {
int dist = pq.top().first;
pair<int, int> curr = pq.top().second;
pq.pop();
if (!visited[curr.first][curr.second]) {
visited[curr.first][curr.second] = -dist;
for (pair<int, pair<int, int>> i : graph[curr.first][curr.second]) {
pq.push({dist - i.first, i.second});
}
}
if (curr == dest) break;
}
cout << visited[dest.first][dest.second] - 1;
return 0;
}
