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#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <algorithm>
#include <queue>
#include <utility> 

using namespace std;

int r,c;
int map[1010][1010];
int time[1010][1010];
int dir[4][2] = {{0,1},{1,0},{0,-1},{-1,0}};
queue< pair<int,int> > J; //声明方式
queue< pair<int,int> > F;

void print()
{
    int i,j;
    for(i = 0; i < r+1; i++)
    {
        for(j = 0; j<c+1; j++)
        {
            printf("%d ",time[i][j]);
        }
        printf("
");
    }
    printf("
");
}

void bfs_fire()
{
    pair<int, int> FF;
    int t, i, x, y;

    while( !F.empty() )
    {            
        FF = F.front();
        F.pop();        
        t = time[FF.first][FF.second];    
        for( i = 0; i < 4; i++)
        {
            x = FF.first + dir[i][0];
            y = FF.second + dir[i][1];
            if(x >= r || x < 0 || y >= c || y < 0)//越界
                continue;            
            if( time[x][y] == 0 )
            {
                time[x][y] = t + 1;
                F.push(make_pair(x, y));
            }
        }
    }
}

void bfs_people()
{
    pair<int,int> JJ;
    int t, i, x, y, ok = 0;    

    while( !J.empty() )
    {    
        JJ = J.front();
        J.pop();
        t = map[JJ.first][JJ.second];
        map[JJ.first][JJ.second] = -1;//标记访问(把这个地方变成墙就行)
        for( i = 0; i < 4; i++)//向四个方向扩展(能走的)
        {
            x = JJ.first + dir[i][0];
            y = JJ.second + dir[i][1]; //pair 具有 first 与 second 成员
            if(x >= r || x < 0 || y >= c || y < 0)//越界
                continue;
            if( map[x][y] == -1 || map[x][y] <= time)//墙或超时
                continue;
            else if( x == r - 1 || x == 0 || y == 0 || y == c - 1 )//边界则走完
            {
                ok = 1;
                printf("%d
", time);
                return;
            }
            else
            {
                J.push(make_pair(x, y));//queue中插入pair   利用make_pair()方法
            }
        }    
    
    }
    if(ok == 0)     
        printf("IMPOSSIBLE
");
}
*/

int main()
{
    int N;
    int i,j;
    char temp;

    freopen("1.txt", "r", stdin);
    scanf("%d", &N);
    getchar();
    while(N--)
    {
        while( !J.empty() ) J.pop(); //注意初始化(清空)队列
        while( !F.empty() ) F.pop();
        memset(map, -1, sizeof(map));
        memset(time, -1, sizeof(time));

        scanf("%d%d", &r, &c);
        getchar();

        for(i = 0; i < r; i++)
        {
            for(j = 0; j < c; j++)
            {//# = -1     F = 1     . = 0
                scanf("%c", &temp);//当读取%c时，注意用getchar吸收掉不必要的回车
                if(temp == '#'){map[i][j] = time[i][j] = -1;}
                else if(temp == 'F'){map[i][j] = time[i][j] = 1;F.push(make_pair(i,j));}      
                else if(temp == 'J'){map[i][j] = 1;time[i][j] = 0;J.push(make_pair(i,j));}      
                else{map[i][j] = time[i][j] = 0;}
            }
            getchar();
        }
        bfs_fire();        
//        bfs_people();
    }
    return 0;
}