import std.conv, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.numeric, std.range, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken().to!int; }
long readLong() { return readToken().to!long; }
real readReal() { return readToken().to!real; }

void chmin(T)(ref T t, in T f) { if (t > f) t = f; }
void chmax(T)(ref T t, in T f) { if (t < f) t = f; }

int binarySearch(T)(in T[] as, in bool delegate(T) test) { int low = -1, upp = cast(int)(as.length); for (; low + 1 < upp; ) { int mid = (low + upp) >> 1; (test(as[mid]) ? low : upp) = mid; } return upp; }
int lowerBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a < val)); }
int upperBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a <= val)); }


enum DX = [+1, 0, -1, 0];
enum DY = [0, +1, 0, -1];
enum N = 100;

int[][] A;
bool[][] vis;
int X, Y, H;

void ask(char c) {
  if (c != '?') {
    writeln(c);
    stdout.flush;
  }
  const res = readToken();
  if (res == "Merry") {
    import core.stdc.stdlib : exit;
    exit(0);
  } else {
    const d = res.to!int;
    foreach (k; 0 .. d + 1) {
      const x = X + DX[H] * k;
      const y = Y + DY[H] * k;
      if (0 <= x && x < N && 0 <= y && y < N) {
        A[x][y] = 1;
      } else {
        break;
      }
    }
    {
      const x = X + DX[H] * (d + 1);
      const y = Y + DY[H] * (d + 1);
      if (0 <= x && x < N && 0 <= y && y < N) {
        A[x][y] = 2;
      }
    }
  }
}

void dfs() {
debug{
writefln("X = %s, Y = %s, H = %s",X,Y,H);
foreach(x;0..N)writeln(A[x]);
}
  vis[X][Y] = true;
  foreach (_; 0 .. 4) {
    const xx = X + DX[H];
    const yy = Y + DY[H];
    if (0 <= xx && xx < N && 0 <= yy && yy < N) {
      if (A[xx][yy] == 1 && !vis[xx][yy]) {
        X += DX[H];
        Y += DY[H];
        ask('F');
        dfs();
        X -= DX[H];
        Y -= DY[H];
        ask('B');
      }
    }
    ++H %= 4;
    ask('L');
  }
}

void main() {
  A = new int[][](N, N);
  vis = new bool[][](N, N);
  X = N / 2;
  Y = N / 2;
  H = 0;
  ask('?');
  dfs();
}