sol_wa

/*
    TASK: AG_Run Loop Peatt
    LANG: CPP
    AUTHOR: PeaTT~
    SOLUTION: BFS + Greedy
*/
#include<bits/stdc++.h>
using namespace std;
int di[]={+1,0,+0,-1},dj[]={+0,-1,+1,+0},dist[1010][1010];
char grid[1010][1010];
queue< pair<int, int> > bfs;
void play(){
    int r,c,a,si,sj,ii,jj,i,j;
    cin>>r>>c>>a;
    for(int i=0;i<r;i++){
        for(int j=0;j<c;j++){
            cin>>grid[i][j];
            if(grid[i][j]=='P')
                si=i,sj=j;
        }
    }
    if(a%2==1){
        cout<<"Can\'t do"<<endl;
        return ;
    }
    bfs.push({si,sj});
    memset(dist,-1,sizeof dist);
    dist[si][sj] = 0;
    while( !bfs.empty() ){      //BFS find dist from P
        i = bfs.front().first, j= bfs.front().second;
        bfs.pop();
        for(int k=0;k<4;k++){
            ii = i+di[k], jj=j+dj[k];
            if(ii<0||jj<0||ii>=r||jj>=c)    continue;
            if(grid[ii][jj]=='#')           continue;
            if(dist[ii][jj]!=-1)            continue;
            dist[ii][jj] = dist[i][j] + 1;
            bfs.push({ii,jj});
        }
    }
    int left = a/2;
    vector<int> ans;
    i = si, j = sj;
    while(left--){
        for(int k=0;k<4;k++){       //Greedy choose
            ii = i+di[k], jj = j+dj[k];
            if(ii<0||jj<0||ii>=r||jj>=c)    continue;
            if(grid[ii][jj]=='#')           continue;
            if(dist[ii][jj]>a/2)            continue; //Checking for valid move
            ans.push_back(k);
            i = ii, j= jj;
            break;
        }
    }
    if(ans.size()==a/2){
        for(auto x: ans){
            if(x==0)    cout<<"D";
            else if(x==1)   cout<<"L";
            else if(x==2)   cout<<"R";
            else if(x==3)   cout<<"U";
        }
        reverse(ans.begin(),ans.end());
        for(auto x: ans){
            if(x==3)    cout<<"D";
            else if(x==2)   cout<<"L";
            else if(x==1)   cout<<"R";
            else if(x==0)   cout<<"U";
        }
        cout<<endl;
    }
    else
        cout<<"Can\'t do"<<endl;
}
int main(){
    ios_base::sync_with_stdio(NULL);
    cin.tie(NULL);
    cout.tie(NULL);
    int q;
    cin >> q;
    while(q--)
        play();
    return 0;
}