#include "bits/stdc++.h"
#define ff first
#define ss second
using namespace std;
const int N = 505;
int dx[] = {1,0,-1,0};
int dy[] = {0,1,0,-1};
int n,m,k;
char a[N][N];
int bfs(int sx,int sy,int x,int y){
queue <pair<int,int>> q;
vector <vector <int>> d(n,vector<int> (m,-1));
d[sx][sy] = 0;
q.push({sx,sy});
while (!q.empty()){
int a1 = q.front().ff,b = q.front().ss;
q.pop();
if (a1 == x && b == y)
return d[x][y];
for (int i = 0;i < 4;i++){
int nx = a1+dx[i],ny = b+dy[i];
if (nx < 0 || nx >= n || ny < 0 || ny >= m)
continue;
if (a[nx][ny] == '#')
continue;
if (~d[nx][ny])
continue;
d[nx][ny] = d[a1][b]+1;
q.push({nx,ny});
}
}
return d[x][y];
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m >> k;
vector <pair<int,int>> c;
int sx = -1,sy = -1,x1=-1,y1=-1;
for (int i = 0;i < n;i++){
for (int j = 0;j < m;j++){
cin >> a[i][j];
if (a[i][j] == 'S')
sx = i,sy = j;
if (a[i][j] == 'X')
c.push_back({i,j});
}
}
assert(k==2);
int d1 = bfs(sx,sy,c[0].ff,c[0].ss);
int d2 = bfs(sx,sy,c[1].ff,c[1].ss);
int dxy = bfs(c[0].ff,c[0].ss,c[1].ff,c[1].ss);
if (d1 == -1 || d2 == -1){
cout << "-1\n";return 0;
}
cout << min(2*d1+2*d2,d1+d2+dxy) << "\n";
}
