#include <bits/stdc++.h>
#define f first
#define s second
#define mk make_pair
using namespace std;
int dx[]={0,0,1,-1};
int dy[]={1,-1,0,0};
int n,m,d;
vector <string> g;
bool valid (int i,int j){
    return i>=0 && j>=0 && i<n && j<m;
}
int x0,y0,xf,yf;
int main (){
    ios_base::sync_with_stdio(0),cin.tie(0);
    cin>>n>>m>>d;
    bool  death[n+4][m+4];
    int dist[n+4][m+4];
    memset(death,false,sizeof death);
    for (int i=0;i<n;i++)
        for (int j=0;j<m;j++) dist[i][j]=1e9;
    g=vector<string> (n);
    for (int i=0;i<n;i++)
        cin>>g[i];
    queue <pair<pair<int,int>,int>> q;
    for (int i=0;i<n;i++)
    for (int j=0;j<m;j++){
        if (g[i][j]=='M')
            q.push(mk(mk(i,j),0));
        if (g[i][j]=='S') x0=i,y0=j;
        if (g[i][j]=='F') xf=i,yf=j;

    }
    while (!q.empty()){
        auto cur =q.front();
        death[cur.f.f][cur.f.s]=1;
        q.pop();
        for (int i=0;i<4;i++){
            int xx=cur.f.f+dx[i];
            int yy=cur.f.s+dy[i];
            if (!valid (xx,yy) or death[xx][yy] or cur.s+1>d) continue;
            q.push(mk(mk(xx,yy),cur.s+1));
        }
    }

    queue <pair<int,int>> pq;
    if (death[x0][y0]==0)
    pq.push(mk(x0,y0));
    dist[x0][y0]=0;
    while (!pq.empty()){
        auto cur =pq.front();
        pq.pop();
        if (cur.f==xf && cur.s==yf){
                cout<<((dist[xf][yf]==1e9)?-1:dist[xf][yf]);
                return 0;
        }
        for (int i=0;i<4;i++){
            int xx=cur.f+dx[i];
            int yy=cur.s+dy[i];
            if (valid (xx,yy) && dist[xx][yy]==(1e9) && death[xx][yy]==false){
            dist[xx][yy]=1+dist[cur.f][cur.s];
            death[xx][yy]=1;
            pq.push(mk(xx,yy));
            }
        }
    }
    cout<<((dist[xf][yf]==1e9)?-1:dist[xf][yf]);



}