/*
入力 validation。WA なら OK。
*/

#include"testlib.h"
#include<bits/stdc++.h>
using namespace std;

const int MIN_N = 1;
const int MAX_N = 1000000000;
const int MIN_M = 1;
const int MAX_M = 200000;

int main(){
	registerValidation();
	int N = inf.readInt(MIN_N, MAX_N, "N");
	inf.readSpace();
	int M = inf.readInt(MIN_M, MAX_M, "M");
	inf.readEoln();
	set<pair<int,int>> st;
	for (int i = 0; i < M; i++){
	    int L = inf.readInt(1, N, "L");
	    inf.readSpace();
	    int R = inf.readInt(L, N, "R");
	    inf.readEoln();
	    st.insert(pair<int,int>(L,R));
	}
	assert(st.size() == M);
	inf.readEof();
	return 0;
}