#include <bits/stdc++.h>
using namespace std;
#define int long long

vector<vector<pair<int, int>>>g;
vector<int>cnt, ans;
map<pair<int, int>, bool>vis;
int tin = 0;

void dfs(int v)
{
	while(!g[v].empty() && vis[{v, g[v].back().first}]) g[v].pop_back();
	if(g[v].empty()) return;
	auto [u, idx] = g[v].back();
	g[v].pop_back();
	cnt[v]--; cnt[u]--;
	vis[{v, u}] = vis[{u, v}] = 1;
	ans[idx] = ++tin % 2;
	dfs(u);
}

signed main() {
    ios::sync_with_stdio(false);cin.tie(nullptr);
	int n; cin >> n;
	vector<pair<int, int>>a(n);
	vector<int>b(n), c(n);
	for(int i = 0; i < n; i++)
	{
		cin >> a[i].first >> a[i].second;
		b[i] = a[i].first;
		c[i] = a[i].second;
	}
	sort(b.begin(), b.end());
	sort(c.begin(), c.end());
	b.erase(unique(b.begin(), b.end()), b.end());
	c.erase(unique(c.begin(), c.end()), c.end());
	map<int, int>id, id2;
	int k = (int)b.size(), l = (int)c.size();
	for(int i = 0; i < k; i++) id[b[i]] = i;
	for(int i = 0; i < l; i++) id2[c[i]] = i+k;
	int m = k+l;
	ans.resize(n); g.resize(m); cnt.resize(m);
	int w = 0;
	for(auto [i, j] : a)
	{
		g[id[i]].push_back({id2[j], w});
		g[id2[j]].push_back({id[i], w++});
		cnt[id[i]]++;
		cnt[id2[j]]++;
	}
	for(int i = 0; i < m; i++)
	{
		if(cnt[i] % 2) dfs(i);
	}
	for(int i = 0; i < m; i++) dfs(i);
	for(int u : ans) cout << (u % 2 ? 'L' : 'F');
}