#include<bits/stdc++.h>
using namespace std;

typedef long long int ll;

vector<vector<int>> swapper;

int turnTableRX[3][3]={{0,0,0},{1,0,-1},{0,0,0}};
int turnTableRY[3][3]={{0,-1,0},{0,0,0},{0,1,0}};

int vx=0,vy=1;
int px=0,py=0;
bool target=false;
int tx,ty;
map<pair<int,int>,int> field;

void print(){
    int x,y;
    for (y=-1;y<5;y++){
        for (x=-3;x<3;x++){
            pair<int,int> p=make_pair(x,y);
            if (px==x&&py==y) cout<<"[";else cout<<" ";
            if (field.count(p)){
                cout << field[p];
            }else{
                cout << "?";
            }

            if (px==x&&py==y) cout<<"]";else cout<<" ";
        }
        cout<<endl;
    }
}

inline bool moveable(int x,int y){
    pair<int,int> p=make_pair(x,y);
    return field.count(p) && field[p];
}

inline void turnLeft(){
    int x=vx,y=vy;
    vx=-turnTableRX[x+1][y+1];
    vy=-turnTableRY[x+1][y+1];
}
inline void turnRight(){
    int x=vx,y=vy;
    vx=turnTableRX[x+1][y+1];
    vy=turnTableRY[x+1][y+1];
}

inline bool isKnown(int x,int y){
    int dx=0,dy=1;
    pair<int,int> p;
    for (int i=0;i<4;i++){
        for (int j=1;j<60;j++){
            p.first=x+dx*j;
            p.second=y+dy*j;
            if (!field.count(p)){
                return false;
            }else if(!field[p]) break;
        }
        int t=dx;
        dx=turnTableRX[dx+1][dy+1];
        dy=turnTableRY[t+1][dy+1];
    }
    return true ;
}

void finalAction(){
    int l;string buff;
    do{
        cout<<"F"<<endl;
        cin >> buff;
    }while(buff[0]!='M');
    exit(0);
}

void check(){
    int l,i;
    if (scanf("%d",&l)<=0) exit(0);
    if (l==20151224) finalAction();
    for (i=1;i<=l;i++){
        field[make_pair(px+vx*i,py+vy*i)]=1;
    }
    field[make_pair(px+vx*i,py+vy*i)]=0;
}

void action(){
    int b;
    if (target){
        // 使ってない
    }else{
        if (isKnown(px,py)){
            map<pair<int,int>,bool> dp;
            queue<vector<int>> q;
            if (moveable(px-1,py)) q.push(vector<int>{px-1,py,-1,0});
            if (moveable(px+1,py)) q.push(vector<int>{px+1,py,1,0});
            if (moveable(px,py-1)) q.push(vector<int>{px,py-1,0,-1});
            if (moveable(px,py+1)) q.push(vector<int>{px,py+1,0,1});
            while (!q.empty()){
                vector<int> &v=q.front();
                dp[make_pair(v[0],v[1])]=true;
                if (isKnown(v[0],v[1])){
                    if (!dp.count(make_pair(v[0]+1,v[1]))
                        && moveable(v[0]+1,v[1])) q.push(vector<int>{v[0]+1,v[1],v[2],v[3]});
                    if (!dp.count(make_pair(v[0]-1,v[1]))
                        && moveable(v[0]-1,v[1])) q.push(vector<int>{v[0]-1,v[1],v[2],v[3]});
                    if (!dp.count(make_pair(v[0],v[1]+1))
                        && moveable(v[0],v[1]+1)) q.push(vector<int>{v[0],v[1]+1,v[2],v[3]});
                    if (!dp.count(make_pair(v[0],v[1]-1))
                        && moveable(v[0],v[1]-1)) q.push(vector<int>{v[0],v[1]-1,v[2],v[3]});
                }else{
                    // target=true;
                    // tx=v[0];ty=v[1];
                    // action();
                    if (v[2]==vx && v[3]==vy){
                        cout<<"F"<<endl;
                        px+=vx;py+=vy;
                    }else{
                        if (turnTableRX[vx+1][vy+1]==v[2] && turnTableRX[vx+1][vy+1]==v[3]){
                            cout<<"R"<<endl;
                            turnRight();
                        }else{
                            cout<<"L"<<endl;
                            turnLeft();
                        }
                    }
                    break;
                }
                q.pop();
            }
        }else{
            cout<<"R"<<endl;
            turnRight();
        }
    }
}

int main(){
    
    field[make_pair(0,0)]=1;
    
    while (true){
        check();
        action();
        //print();
    }
    
    return 0;
}