#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define MT make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define RT return
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;

const int DY[] = { -1,0,1,0 };
const int DX[] = { 0,1,0,-1 };

const int INF = 20151224;

stack<char> hs;
int dir;
int order(char c) {
    if (c == 'R' || c == 'F')hs.push(c);
    if (c == 'R') (dir += 1) %= 4;
    else if (c == 'L')(dir += 3) %= 4;
    cout << c << endl;
    string res;
    cin >> res;
    if (res[0] == 'M')
        exit(0);
    return stoi(res);
}

int A[410][410];
const int OS = 205;

void dfs(int y, int x) {
    if (A[y][x]++)return;
    while (dir != 3) order('R');
    rep(i, 4) {
        int movable = order('R');
        int ny = DY[i] + y;
        int nx = DX[i] + x;
        if (!movable)A[ny][nx] = 1;
        if (!A[ny][nx]) {
            int stk_size = sz(hs);
            order('F');
            dfs(ny, nx);
            while (sz(hs) > stk_size) {
                char c = hs.top();
                hs.pop();
                if (c == 'R')order('L');
                else order('B');
            }
        }
    }
}

void solve() {
    {string s; cin >> s; }
    dfs(OS, OS);
}

int main() {
	// ios::sync_with_stdio(false);
	// cin.tie(0);
	cout << fixed << setprecision(15);
	solve();
	return 0;
}