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

const ll N_min = 1;
const ll N_max = 1'000'000'000'000'000'000;
const ll M_min = 1;
const ll M_max = 100'000;

int main() {
	registerValidation();
	ll N = inf.readLong(N_min, N_max);
	inf.readSpace();
	ll M = inf.readLong(M_min, M_max);
	inf.readEoln();
	for (int i = 0; i < M; i++) {
		ll L = inf.readLong(1, N);
		inf.readSpace();
		ll R = inf.readLong(1, N);
		inf.readEoln();
		ensure(L <= R);
	}
	inf.readEof();
}