There is a pond with a rectangular shape. The pond is divided into a grid with H rows and W columns of squares. We will denote the square at the i-th row from the top and j-th column from the left by (i,\ j).

Some of the squares in the pond contains a lotus leaf floating on the water. On one of those leaves, S, there is a frog trying to get to another leaf T. The state of square (i,\ j) is given to you by a character a_{ij}, as follows:

* `.` : A square without a leaf.
* `o` : A square with a leaf floating on the water.
* `S` : A square with the leaf S.
* `T` : A square with the leaf T.



The frog will repeatedly perform the following action to get to the leaf T: "jump to a leaf that is in the same row or the same column as the leaf where the frog is currently located."

Snuke is trying to remove some of the leaves, other than S and T, so that the frog cannot get to the leaf T. Determine whether this objective is achievable. If it is achievable, find the minimum necessary number of leaves to remove.

Constraints

* 2 ≤ H, W ≤ 100
* a_{ij} is `.`, `o`, `S` or `T`.
* There is exactly one `S` among a_{ij}.
* There is exactly one `T` among a_{ij}.

Input

Input is given from Standard Input in the following format:


H W
a_{11} ... a_{1W}
:
a_{H1} ... a_{HW}


Output

If the objective is achievable, print the minimum necessary number of leaves to remove. Otherwise, print `-1` instead.

Examples

Input

3 3
S.o
.o.
o.T


Output

2


Input

3 4
S...
.oo.
...T


Output

0


Input

4 3
.S.
.o.
.o.
.T.


Output

-1


Input

10 10
.o...o..o.
....o.....
....oo.oo.
..oooo..o.
....oo....
..o..o....
o..o....So
o....T....
....o.....
........oo


Output

5
import static java.lang.Math.*;
import static java.util.Arrays.*;
import java.util.*;

import java.io.*;

public class Main {
	
	int H, W;
	char[][] s;
	void solve() {
		H = sc.nextInt();
		W = sc.nextInt();
		s = new char[H][];
		for (int i = 0; i < H; i++) s[i] = sc.next().toCharArray();

		int rS = -1, cS = -1;
		int rT = -1, cT = -1;
		for (int i = 0; i < H; i++)
			for (int j = 0; j < W; j++) {
				if (s[i][j] == 'S') { rS = i; cS = j; }
				if (s[i][j] == 'T') { rT = i; cT = j; }
			}
		if (rS == rT || cS == cT) {
			out.println(-1);
			return ;
		}
		
		{ char[] t = s[rS]; s[rS] = s[0]; s[0] = t; }
		{ char[] t = s[rT]; s[rT] = s[H-1]; s[H-1] = t; }
		for (int i = 0; i < H; i++) {
			char t = s[i][cS]; s[i][cS] = s[i][0]; s[i][0] = t; 
		}
		for (int i = 0; i < H; i++) {
			char t = s[i][cT]; s[i][cT] = s[i][W-1]; s[i][W-1] = t; 
		}
//		for (int i = 0; i < H; i++) {
//			tr(new String(s[i]));
//		}
		
		boolean[][] vis1 = new boolean[H][W];
		boolean[][] vis2 = new boolean[H][W];
		dfs(0, 0, vis1);
		dfs(H-1, W-1, vis2);
		for (int i = 0; i < H; i++) {
			for (int j = 0; j < W; j++) {
				if (s[i][j] == 'o') {
					if (!vis2[i][j] || !vis2[i][j]) s[i][j] = '.';
				}
			}
		}
//		for (int i = 0; i < H; i++) {
//			tr(new String(s[i]));
//		}
		
		V[][][] vs = new V[H][W][2];
		for (int i = 0; i < H; i++) {
			for (int j = 0; j < W; j++) {
				V from = new V();
				V to = new V();
				vs[i][j][0] = from;
				vs[i][j][1] = to;
				from.add(to, 1);
			}
		}
		make_graph(vs);
		
		int ans = dinic(vs[0][0][1], vs[H-1][W-1][0]);
		out.println(ans);
	}
	
	void make_graph(V[][][] vs) {
		int[] q = new int[H * W * 2];
		boolean[][] vis = new boolean[H][W];
		
		int a = 0, b = 0;
		q[b++] = 0;
		q[b++] = 0;
		vis[0][0] = true;
		while (a < b) {
			int r = q[a++];
			int c = q[a++];
			if (s[r][c] == 'T') continue;
			for (int i = 0; i < H; i++) if (s[i][c] == 'o' || s[i][c] == 'T') {
				vs[r][c][1].add(vs[i][c][0], INF);
				if (!vis[i][c]) {
					vis[i][c] = true;
					q[b++] = i; q[b++] = c;
				}
			}
			for (int j = 0; j < W; j++) if (s[r][j] == 'o' || s[r][j] == 'T') {
				vs[r][c][1].add(vs[r][j][0], INF);
				if (!vis[r][j]) {
					vis[r][j] = true;
					q[b++] = r; q[b++] = j;
				}
				dfs(r, j, vis);
			}
		}
	}
	
	void dfs(int r, int c, boolean[][] vis) {
		if (vis[r][c]) return;
		vis[r][c] = true;
		for (int i = 0; i < H; i++) if (s[i][c] == 'o') {
			dfs(i, c, vis);
		}
		for (int j = 0; j < W; j++) if (s[r][j] == 'o') {
			dfs(r, j, vis);
		}
	}

	static final int INF = 1001001001;
	
	
	int dinic(V s, V t) {
		int flow = 0;
		for (int p = 1;; p++) {
			Queue<V> que = new LinkedList<V>();
			s.level = 0;
			s.p = p;
			que.offer(s);
			while (!que.isEmpty()) {
				V v = que.poll();
				v.iter = v.es.size() - 1;
				for (E e : v.es)
					if (e.to.p < p && e.cap > 0) {
						e.to.level = v.level + 1;
						e.to.p = p;
						que.offer(e.to);
					}
			}
			if (t.p < p) return flow;
			for (int f; (f = dfs(s, t, INF)) > 0;) flow += f;
		}
	}

	int dfs(V v, V t, int f) {
		if (v == t) return f;
		for (; v.iter >= 0; v.iter--) {
			E e = v.es.get(v.iter);
			if (v.level < e.to.level && e.cap > 0) {
				int d = dfs(e.to, t, Math.min(f, e.cap));
				if (d > 0) {
					e.cap -= d;
					e.rev.cap += d;
					return d;
				}
			}
		}
		return 0;
	}

	class V {
		ArrayList<E> es = new ArrayList<E>();
		int level, p, iter;
		
		void add(V to, int cap) {
			E e = new E(to, cap);
			E rev = new E(this, 0);
			e.rev = rev;
			rev.rev = e;
			es.add(e);
			to.es.add(rev);
		}
	}

	class E {
		V to;
		E rev;
		int cap;

		E(V to, int cap) {
			this.to = to;
			this.cap = cap;
		}
	}
	static void tr(Object... os) { System.err.println(deepToString(os)); }
	static void tr(int[][] as) { for (int[] a : as) tr(a); }

	void print(int[] a) {
		out.print(a[0]);
		for (int i = 1; i < a.length; i++) out.print(" " + a[i]);
		out.println();
	}

	public static void main(String[] args) throws Exception {
		new Main().run();
	}

	MyScanner sc = null;
	PrintWriter out = null;
	public void run() throws Exception {
		sc = new MyScanner(System.in);
		out = new PrintWriter(System.out);
		for (;sc.hasNext();) {
			solve();
			out.flush();
		}
		out.close();
	}

	class MyScanner {
		String line;
		BufferedReader reader;
		StringTokenizer tokenizer;

		public MyScanner(InputStream stream) {
			reader = new BufferedReader(new InputStreamReader(stream));
			tokenizer = null;
		}
		public void eat() {
			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
				try {
					line = reader.readLine();
					if (line == null) {
						tokenizer = null;
						return;
					}
					tokenizer = new StringTokenizer(line);
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}
		}
		public String next() {
			eat();
			return tokenizer.nextToken();
		}
		public String nextLine() {
			try {
				return reader.readLine();
			} catch (IOException e) {
				throw new RuntimeException(e);
			}
		}
		public boolean hasNext() {
			eat();
			return (tokenizer != null && tokenizer.hasMoreElements());
		}
		public int nextInt() {
			return Integer.parseInt(next());
		}
		public long nextLong() {
			return Long.parseLong(next());
		}
		public double nextDouble() {
			return Double.parseDouble(next());
		}
		public int[] nextIntArray(int n) {
			int[] a = new int[n];
			for (int i = 0; i < n; i++) a[i] = nextInt();
			return a;
		}
	}
}