#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>
#include <numeric>
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
constexpr long long MAX = 5100000;
constexpr long long INF = 1LL << 60;
constexpr int inf = 1000000007;
constexpr long long mod = 1000000007LL;
//constexpr long long mod = 998244353LL;
const long double PI = acos((long double)(-1));

using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;

void insert(ll l, ll r, set<pair<ll, ll>>& st, ll &mx) {
	auto itr = st.upper_bound({ r + 1, INF });
	if (itr == st.begin()) {
		st.emplace(l, r);
		chmax(mx, r - l + 1);
	}else{
		itr = prev(itr);
		while (l - 1 <= itr->second) {
			chmax(r, itr->second);
			chmin(l, itr->first);
			st.erase(itr);
			if (st.empty()) break;
			itr = st.upper_bound({ r + 1,INF });
			if (itr == st.begin()) break;
			itr = prev(itr);
		}
		st.emplace(l, r);
		chmax(mx, r - l + 1);
	}
}
int main()
{
	/*
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	*/
	ll D, Q; scanf("%lld %lld", &D, &Q);
	ll res = 0;
	set<pair<ll, ll>> st; st.emplace(INF, INF);
	while (Q--) {
		ll a, b; scanf("%lld %lld", &a, &b);
		insert(a, b, st, res);
		printf("%lld\n", res);
	}
	return 0;
}