$o={0,[R0,{0,[RRRL1R3LRLRLRRLRLLRLRRRLRLR1L1RLRL],1,[FR2RLR12R4RLRLRL2LRLRRLR1L2LLRLRLRRRLRL],2,[F1L0,{2,[FLRRLLRLR6RRLRLLRLRLRRLRRL2LRR6LRLLRLLRLRLRRR6L],4,[F2R7L12R7LRL]}],5,[F1LL1R]}],1,[FLLRRRRLR1LRL3LRLLRR2LLR],2,[R0,{0,[LLLLLLL],1,[LL],2,[LRRLLLRRLR],3,[B8R],4,[FLRRLR],8,[FLRR]}],3,[L1L7RL3R],4,[FRL7LLR2R3L2RLLRRLL2RRL],14,[FRRRRRRRRLLLLLLLLR],16,[FL8L]};

sub move {$|=print"@_\n";<>}

$t=<>;
while(1){
	while($t>99){
		$t=move F;
	}
	exit if $t=~M;
	last if !$o;
	$o=$o->{$t+0};
	$_=$o->[0];
	$o=$o->[1];
	while(s/(.)(\d*)//){
		my$_=$1;
		my$s=$2;
		$t=move$_ if/R/||/L/;
		$_=/B/?B:F;
		while($s eq ''?$t>0:$s--){
			$t=move$_;
		}
	}
}
do{
	$d-=print"R\n";
	$d+=print"L\n"while<><++$|||$m[$y=($x+30**($d&=3))%901]^($m[$x]=$d^4)^2&&$m[$y];
	$x=$y;
	print"F\n";
}until<>=~M;