import std;

void main () {
    int N = readln.chomp.to!int;

    // ジグザグで通りそう
    auto command = new byte[](2 * N);
    foreach (i; 0 .. N) {
        command[2 * i] = 'R';
        command[2 * i + 1] = 'D';
    }

    foreach (c; command) {
        writeln(c.to!char);
        stdout.flush;

        int v = readln.chomp.to!int;
        if (v == 1) return;
        if (v == -1) return;
    }
}

void read (T...) (string S, ref T args) {
    import std.conv : to;
    import std.array : split;
    auto buf = S.split;
    foreach (i, ref arg; args) {
        arg = buf[i].to!(typeof(arg));
    }
}