using System.Collections.Generic;
using static System.Math;
using System;

public class PriorityQueue<T> where T : IComparable
{
    private IComparer<T> _comparer = null;
    private int _type = 0;
    private T[] _heap;
    private int _sz = 0;
    private int _count = 0;
    /// <summary>
    /// Priority Queue with custom comparer
    /// </summary>
    public PriorityQueue(int maxSize, IComparer<T> comparer)
    {
        _heap = new T[maxSize];
        _comparer = comparer;
    }

    /// <summary>
    /// Priority queue
    /// </summary>
    /// <param name="maxSize">max size</param>
    /// <param name="type">0: asc, 1:desc</param>
    public PriorityQueue(int maxSize, int type = 0)
    {
        _heap = new T[maxSize];
        _type = type;
    }
    private int Compare(T x, T y)
    {
        if (_comparer != null) return _comparer.Compare(x, y);
        return _type == 0 ? x.CompareTo(y) : y.CompareTo(x);
    }
    public void Push(T x)
    {
        _count++;
        //node number
        var i = _sz++;
        while (i > 0)
        {
            //parent node number
            var p = (i - 1) / 2;

            if (Compare(_heap[p], x) <= 0) break;

            _heap[i] = _heap[p];
            i = p;
        }
        _heap[i] = x;
    }
    public T Pop()
    {
        _count--;
        T ret = _heap[0];
        T x = _heap[--_sz];

        int i = 0;
        while (i * 2 + 1 < _sz)
        {
            //children
            int a = i * 2 + 1;
            int b = i * 2 + 2;

            if (b < _sz && Compare(_heap[b], _heap[a]) < 0) a = b;

            if (Compare(_heap[a], x) >= 0) break;

            _heap[i] = _heap[a];
            i = a;
        }
        _heap[i] = x;
        return ret;
    }
    public int Count()
    {
        return _count;
    }
    public T Peek()
    {
        return _heap[0];
    }
    public bool Contains(T x)
    {
        for (int i = 0; i < _sz; i++) if (x.Equals(_heap[i])) return true;
        return false;
    }
    public void Clear()
    {
        while (this.Count() > 0) this.Pop();
    }
    public IEnumerator<T> GetEnumerator()
    {
        var ret = new List<T>();
        while (this.Count() > 0)
        {
            ret.Add(this.Pop());
        }
        foreach (var r in ret)
        {
            this.Push(r);
            yield return r;
        }
    }
    public T[] ToArray()
    {
        T[] array = new T[_sz];
        int i = 0;
        foreach (var r in this)
        {
            array[i++] = r;
        }
        return array;
    }
}

public class Edge
{
    public int to { get; set; }
    public long d { get; set; }
}

public class Node : IComparable
{
    public int id { get; set; }
    public long d { get; set; }
    public int CompareTo(object obj)
    {
        var x = (Node)obj;
        if (this.d > x.d) return 1;
        else if (this.d == x.d) return 0;
        else return -1;
    }
}

public class P
{
    public int x { get; set; }
    public int y { get; set; }
}

public class hello
{
    public static int h, w;
    public static int[] dx, dy;

    public static void Main()
    {
        dx = new int[] { -2, -1, -1, 0, 0, 0, 1, 1, 2 };
        dy = new int[] { 1, 1, 2, 1, 2, 3, 1, 2, 1 };
        while (true)
        {
            string[] line = Console.ReadLine().Trim().Split(' ');
            w = int.Parse(line[0]);
            h = int.Parse(line[1]);
            var hw = w * h;
            if (w == 0 && h == 0) break;
            var map = new int[h, w];
            var sp = new List<int>();
            var tp = new List<int>();
            var a = new List<Edge>[hw * 2];
            for (int i = 0; i < h * w * 2; i++) a[i] = new List<Edge>();
            for (int i = 0; i < h; i++)
            {
                line = Console.ReadLine().Trim().Split(' ');
                for (int j = 0; j < w; j++)
                {
                    var t = line[j];
                    if (t == "S") { sp.Add(getNextL(i, j)); sp.Add(getNextr(i, j)); }
                    else if (t == "T") { tp.Add(getNextL(i, j)); tp.Add(getNextr(i, j)); }
                    else if (t == "X") map[i, j] = -1;
                    else map[i, j] = int.Parse(line[j]);
                }
            }
            for (int i = 0; i < h; i++)
                for (int j = 0; j < w; j++)
                    if (map[i, j] != -1)
                    {
                        for (int k = 0; k < 9; k++)
                        {
                            var nextx = i + dx[k];
                            var nextry = j + dy[k];
                            var nextLy = j - dy[k];
                            if (nextx >= 0 && nextx < h && nextry >= 0 &&  nextry < w && map[nextx, nextry] >= 0)
                            {
                                var tt = getNextr(nextx, nextry);
                                a[getNextL(i, j)].Add(new Edge { to = tt, d = map[nextx, nextry] });
                            }
                            if (nextx >= 0 && nextx < h && nextLy >= 0 && nextLy < w   && map[nextx, nextLy] >= 0)
                            {
                                var tt = getNextL(nextx, nextLy);
                                a[getNextr(i, j)].Add(new Edge { to = tt, d = map[nextx, nextLy] });
                            }
                        }
                    }
            var ans = 9999999999999;
            foreach (var x in sp)
            {
                var pq = new PriorityQueue<Node>(hw * 9 + 10000);
                var mind = new long[hw * 2];
                for (int i = 0; i < hw * 2; i++) mind[i] = 9999999999999;
                goDijk(pq, a, x, hw, mind);
                foreach (var y in tp)
                    ans =Min(ans, mind[y]);
            }
            Console.WriteLine(ans == 9999999999999? -1:ans);
        }
    }
    static void goDijk(PriorityQueue<Node> pq, List<Edge>[] aa, int r, int n, long[] mind)
    {
        pq.Push(new Node { id = r, d = 0 });
        while (pq.Count() > 0)
        {
            var targ = pq.Pop();
            var nowd = targ.d;
            var nowid = targ.id;
            if (mind[nowid] < nowd) continue;
            mind[nowid] = nowd;
            foreach (var x in aa[nowid])
                if (nowd + x.d < mind[x.to])
                {
                    mind[x.to] = nowd + x.d;
                    pq.Push(new Node { id = x.to, d = nowd + x.d });
                }
        }
    }
    static int getNextL(int x, int y) => w * x + y;
    static int getNextr(int x, int y) => w * x + y + h * w;
}



Measured memory_bytes: 41000