#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 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()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

const int INF = 20151224;

int order(char c){
    printf("%c\n", c);
    fflush(stdout);
    char res_[20];
    scanf("%s", &res_);
    string res(res_);
    if(res == "Merry Christmas!")
        exit(0);
    return stoi(res);
}

int rnd(int mod){
    return rand() % mod;
}

int main(){
    while(1){
        int cnt = rnd(4);
        int res = 0;
        rep(i, cnt)
            res = order('L');
        if(res == 0)continue;
        if(res == INF)
            while(1)order('F');
        int len = rnd(res) + 1;
        rep(i, len)order('F');
    }
}