#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#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];
pair<int, int> graph[1002][1002][8], 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][0] = {i - 1, j};
if (open[i + 1][j]) graph[i][j][1] = {i + 1, j};
if (open[i][j - 1]) graph[i][j][2] = {i, j - 1};
if (open[i][j + 1]) graph[i][j][3] = {i, j + 1};
}
queue<pair<int, int>> q;
FOR(i, 1, n + 1) FOR(j, 1, m + 1) {
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();
int x = curr.first, y = curr.second;
q.pop();
FOR(i, 0, 4) {
if (!to_wall[graph[x][y][i].first][graph[x][y][i].second]) {
to_wall[graph[x][y][i].first][graph[x][y][i].second] =
to_wall[x][y] + 1;
q.push(graph[x][y][i]);
}
}
}
bool has = false;
FOR(i, 0, n + 1) FOR(j, 0, m + 1) {
if (!open[i][j])
has = false;
else {
if (!has)
graph[i][j][4] = {i, j};
else
graph[i][j][4] = graph[i][j - 1][4];
has = true;
}
}
FOR(j, 0, m + 1) FOR(i, 0, n + 1) {
if (!open[i][j])
has = false;
else {
if (!has)
graph[i][j][5] = {i, j};
else
graph[i][j][5] = graph[i - 1][j][5];
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)
graph[i][j][6] = {i, j};
else
graph[i][j][6] = graph[i][j + 1][6];
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)
graph[i][j][7] = {i, j};
else
graph[i][j][7] = graph[i + 1][j][7];
has = true;
}
}
priority_queue<pair<int, pair<int, int>>> pq;
pq.push({-1, src});
while (pq.size()) {
pair<int, int> curr = pq.top().second;
int dist = pq.top().first, x = curr.first, y = curr.second;
pq.pop();
if (!visited[x][y]) {
visited[x][y] = -dist;
FOR(i, 0, 4)
if (graph[x][y][i].first) pq.push({dist - 1, graph[x][y][i]});
FOR(i, 4, 8)
if (graph[x][y][i].first)
pq.push({dist - to_wall[x][y], graph[x][y][i]});
}
if (curr == dest) break;
}
cout << visited[dest.first][dest.second] - 1;
return 0;
}
