// Slower C++ solution:
#include "bits/stdc++.h"

#define ll long long

#define lld long double

#define MOD 1000000007

#define inf 1000000000000000000ll

#define pii pair<int,int>

#define f first

#define s second

#define pb push_back

#define mp make_pair

#define all(v) v.begin(),v.end()

#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

ll power(ll x,ll y, ll md=inf){ll res = 1;x%=md;while(y){if(y&1)res = (res*x)%md;x *= x; if(x>=md) x %= md; y >>= 1;}return res;}

 

using namespace std;





#define endl '\n'

#define int ll



signed main() {

	fast;



	int h,w;

	cin>>h>>w;



	pii v[200002];

	for(int i=0;i<h;i++) cin>>v[i].f>>v[i].s;



	map<int,int> mp;

	for(int i=1;i<=w;i++) mp[i] = 0;



	map<int,int> mini = {{0,w}};



	for(int i=0;i<h;i++) {

		int l = v[i].f;

		int r = v[i].s;



		auto it = mp.lower_bound(l);

		int mn = inf;



		while(it!=mp.end() && it->f <= r) {

			mn = min(mn, r+1-(it->f)+(it->s));

			auto it1 = it++;

			mini[it1->s]--;

			if(mini[it1->s]==0) mini.erase(it1->s);

			mp.erase(it1);

		}



		if(r+1<=w && mn<inf) {

			if(it!=mp.end() && it->f == r + 1) {

				if(it->s > mn) {

					mini[it->s]--;

					if(mini[it->s]==0) mini.erase(it->s);

					mini[mn]++;

					it->s = mn;

				}

			}

			else {

				mp.insert({r+1,mn});

				mini[mn]++;

			}

		}



		if(mini.size()) cout<<mini.begin()->f+i+1<<endl;

		else cout<<-1<<endl;



	}

}

// Faster C++ solution for the same problem (measured speedup: 1.6157414647378432x):
#include "bits/stdc++.h"

#define ll long long

#define lld long double

#define MOD 1000000007

#define inf 1000000007

#define pii pair<int,int>

#define f first

#define s second

#define pb push_back

#define mp make_pair

#define all(v) v.begin(),v.end()

#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

// ll power(ll x,ll y, ll md=inf){ll res = 1;x%=md;while(y){if(y&1)res = (res*x)%md;x *= x; if(x>=md) x %= md; y >>= 1;}return res;}

 

using namespace std;





#define endl '\n'

// #define int ll



signed main() {

	fast;



	int h,w;

	cin>>h>>w;



	pii v[200002];

	for(int i=0;i<h;i++) cin>>v[i].f>>v[i].s;



	map<int,int> mp;

	for(int i=1;i<=w;i++) mp[i] = 0;



	map<int,int> mini = {{0,w}};



	for(int i=0;i<h;i++) {

		int r = v[i].s;



		auto it = mp.lower_bound(v[i].f);





		if(r==w) {

			while(it!=mp.end() && it->f <= r) {

				auto it1 = it++;

				auto it2 = mini.find(it1->s);

				if(it2->s==1) mini.erase(it2);

				else it2->s --;

				mp.erase(it1);

			}



			if(mini.size()) cout<<mini.begin()->f+i+1<<endl;

			else cout<<-1<<endl;

		}

		else {

			int mn = inf;



			while(it!=mp.end() && it->f <= r) {

				mn = min(mn, r+1-(it->f)+(it->s));

				auto it1 = it++;

				auto it2 = mini.find(it1->s);

				if(it2->s==1) mini.erase(it2);

				else it2->s --;

				mp.erase(it1);

			}



			if(mn<inf) {

				if(it!=mp.end() && it->f == r + 1) {

					if(it->s > mn) {

						auto it1 = mini.find(it->s);

						if(it1->s ==1) mini.erase(it1);

						else it1->s --;

						mini[mn]++;

						it->s = mn;

					}

				}

				else {

					mp.insert({r+1,mn});

					mini[mn]++;

				}

				cout<<mini.begin()->f+i+1<<endl;

			}

			else {

				if(mini.size()) cout<<mini.begin()->f+i+1<<endl;

				else cout<<-1<<endl;

			}



		}



	}

}