#include <iostream>
#include <algorithm>
using namespace std;
using i64 = long long;

class range {private: struct I{int x;int operator*(){return x;}bool operator!=(I& lhs){return x<lhs.x;}void operator++(){++x;}};I i,n;
public:range(int n):i({0}),n({n}){}range(int i,int n):i({i}),n({n}){}I& begin(){return i;}I& end(){return n;}};

void output(char ch) {
  putchar(ch);
  putchar('\n');
  fflush(stdout);
}

int main(void) {
  while(true) {
    string s; getline(cin, s);
    if(s == "Merry Christmas!") { break; }
    int x = stoi(s);
    if(x > 0) { output('F'); }
    else { output('L'); }
  }
  return 0;
}