#include "bits/stdc++.h"
#include <random>
using namespace std;
using ll    =long long;    using dd   =double;        using pll    =pair<ll, ll>;  using tll    =tuple<ll,ll,ll>;using qll=tuple<ll,ll,ll,ll>;
using vll   =vector<ll>;   using vdd  =vector<dd>;    using vpll   =vector<pll>;   using vtll   =vector<tll>;    using vqll   =vector<qll>;
using vvll  =vector<vll>;  using vvdd =vector<vdd>;   using vvpll  =vector<vpll>;  using vvtll  =vector<vtll>;   using vvqll  =vector<vqll>;
using vvvll =vector<vvll>; using vvvdd=vector<vvdd>;  using vvvpll =vector<vvpll>; using vvvtll =vector<vvtll>;  using vvvqll =vector<vvqll>;
using vvvvll=vector<vvvll>;using vvvvdd=vector<vvvdd>;using vvvvpll=vector<vvvpll>;using vvvvtll=vector<vvvtll>; using vvvvqll=vector<vvvqll>;

constexpr ll INF = 1LL << 60;
constexpr dd EPS = 1e-11;
constexpr dd PI  = 3.1415926535897932;

//cin,cout高速化のおまじない＋桁数指定
struct Fast{
	Fast(){
		cin.tie(0);
		ios::sync_with_stdio(false);
		cout << fixed << setprecision(std::numeric_limits<double>::max_digits10);
	}
} fast;

#define REPS(i, S, E) for (ll i = (S); i <= (E); i++)
#define rep(i, S, E)  for (ll i = (S); i <= (E); i++)
#define REP(i, N) REPS(i, 0, (N)-1)
#define DEPS(i, S, E) for (ll i = (E); i >= (S); i--)
#define dep(i, E, S)  for (ll i = (E); i >= (S); i--)
#define DEP(i, N) DEPS(i, 0, (N)-1)
#define EACH(e, v) for (auto&& e : v)
#define each(e, v) for (auto&& e : v)
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()

template<class T> inline bool chmax(T &a, T b) { if (a < b) { a = b; return true; }return false; }
template<class T> inline bool chmin(T &a, T b) { if (a > b) { a = b; return true; }return false; }
template<class T> inline T MaxE(vector<T>&v,ll S,ll E){T m=v[S]; REPS(i,S,E)chmax(m,v[i]); return m;}//v[S]～v[E]の最大値
template<class T> inline T MinE(vector<T>&v,ll S,ll E){T m=v[S]; REPS(i,S,E)chmin(m,v[i]); return m;}//v[S]～v[E]の最小値
template<class T> inline T MaxE(vector<T> &v, ll N) { return MaxE(v, 0, N - 1); } //先頭N個中の最大値
template<class T> inline T MinE(vector<T> &v, ll N) { return MinE(v, 0, N - 1); }
template<class T> inline T MaxE(vector<T> &v) { return MaxE(v, (ll)v.size()); }
template<class T> inline T MinE(vector<T> &v) { return MinE(v, (ll)v.size()); }
template<class T> inline ll MaxI(vector<T>&v,ll S,ll E){ll m=S; REPS(i,S,E){if(v[i]>v[m])m=i;} return m;}
template<class T> inline ll MinI(vector<T>&v,ll S,ll E){ll m=S; REPS(i,S,E){if(v[i]<v[m])m=i;} return m;}
template<class T> inline ll MaxI(vector<T> &v, ll N) { return MaxI(v, 0, N - 1); }
template<class T> inline ll MinI(vector<T> &v, ll N) { return MinI(v, 0, N - 1); }
template<class T> inline ll MaxI(vector<T> &v) { return MaxI(v, (ll)v.size()); }
template<class T> inline ll MinI(vector<T> &v) { return MinI(v, (ll)v.size()); }
template<class T> inline T Sum(vector<T> &v, ll S,ll E){ T s=v[S]; REPS(i,S+1,E)s+=v[i]; return s; }
template<class T> inline T Sum(vector<T> &v, ll N) { return Sum(v, 0, N - 1); }
template<class T> inline T Sum(vector<T> &v) { return Sum(v, v.size()); }
template<class T> inline ll sz(T &v){ return (ll)v.size(); }
template<class T> inline T POW(T a, ll n){ T r=1; for (; n>0; n>>=1, a*=a){ if (n&1)r*=a; } return r; }
inline ll POW(int a, ll n){ return POW((ll)a, n); }
inline ll CEIL(ll a, ll b){ return (a+b-1)/b; }
ll Gcd(ll a, ll b){ return (b==0) ? a : Gcd(b, a%b); }
ll Lcm(ll a, ll b){ return a * b / Gcd(a, b); }
inline ll MSB(ll a){for(ll o=63,x=-1;;){ll m=(o+x)/2; if(a<(1LL<<m))o=m; else x=m; if(o-x==1)return x;}}
inline ll Upper2N(ll s) { return 1LL<<MSB(s)<<1; }//s<2^nなる最小の2^n
inline vll Bit2Idx(ll m){vll v; for(ll i=0;m;m>>=1,i++) if(m&1)v.push_back(i); return v;}
inline ll BitNum(ll m){ for (ll c=0;; m>>=1){ c+=m&1; if (!m)return c; } }
inline ll Bit(ll s, ll i){ return (s>>i)&1; } //sの第ibit i=0-63
[[nodiscard]] inline ll BitOn(ll s, ll i){ return s|(1LL<<i); } //sの第ibitON i=0-63
[[nodiscard]] inline ll BitOff(ll s, ll i){ return s&~(1LL<<i); } //sの第ibitOFF i=0-63
[[nodiscard]] inline ll BitCut(ll s, ll i){ return s & ((1LL<<++i)-1); }//sの第0～第ibitを抽出
inline vll str2num(string &s, ll N) {vll v(N); REP(i, N) v[i]=(ll)(s[i]-'0'); return v;}
inline vll ALP2num(string &s, ll N) {vll v(N); REP(i, N) v[i]=(ll)(s[i]-'A'); return v;}
inline vll alp2num(string &s, ll N) {vll v(N); REP(i, N) v[i]=(ll)(s[i]-'a'); return v;}
template<class T> inline ll FloorIdx(vector<T> &v, T x){ return upper_bound(ALL(v), x)-v.begin()-1; }
template<class T> inline ll CeilIdx(vector<T> &v, T x){ return lower_bound(ALL(v), x)-v.begin(); }
template<class T> inline ll UnderNumOf(vector<T> &v, T x){ //sort済vのx以下の個数を得る
	return upper_bound(v.begin(), v.end(), x) - v.begin(); }
template<class T, class Pr> inline ll UnderNumOf(vector<T> &v, T x, Pr pred){ //x以下個数
	return upper_bound(v.begin(), v.end(), x, pred) - v.begin(); }
template<class T> inline ll OverNumOf(vector<T> &v, T x){ //sort済vのx以上の個数を得る
	return (ll)v.size() - (lower_bound(v.begin(), v.end(), x) - v.begin()); }
template<class T, class Pr> inline ll OverNumOf(vector<T> &v, T x, Pr pred){ //x以上の個数
	return (ll)v.size() - (lower_bound(v.begin(), v.end(), x, pred) - v.begin()); }

template<class T=ll> inline vector<T> cinv(ll N){ vector<T> v(N); REP(i, N)cin>>v[i]; return v;}
template<class T, class S> inline vector<pair<T, S>> cinv2(ll N){
	vector<pair<T, S>> v(N); REP(i,N){cin>>v[i].first>>v[i].second;} return v; }
template<class T> inline vector<T> cinv2(ll N){
	vector<T> v(N); REP(i, N){ll a, b; cin>>a>>b; v[i]={a,b};} return v;}
template<class T,class S,class R> inline vector<tuple<T, S, R>> cinv3(ll N){
	vector<tuple<T,S,R>> v(N); REP(i,N){cin>>get<0>(v[i])>>get<1>(v[i])>>get<2>(v[i]);} return v;}
template<class T> inline vector<T> cinv3(ll N){
	vector<T> v(N); REP(i, N){ll a,b,c; cin>>a>>b>>c; v[i]={a,b,c};} return v;}
template<class T,class S,class R,class Q> inline vector<tuple<T,S,R,Q>> cinv4(ll N){
	vector<tuple<T,S,R,Q>> v(N); REP(i,N){cin>>get<0>(v[i])>>get<1>(v[i])>>get<2>(v[i])>>get<3>(v[i]);} return v;}
template<class T> inline vector<T> cinv4(ll N){
	vector<T> v(N); REP(i, N){ll a,b,c,d; cin>>a>>b>>c>>d; v[i]={a,b,c,d};} return v;}
template<class T=ll> inline vector<vector<T>> cinvv(ll N, ll M){
	vector<vector<T>> vv(N); REP(i, N) vv[i] = cinv(M); return vv;}
template<class T> inline void coutv(vector<T> &v, string d=" "){
	ll N=(ll)v.size(); REP(i,N){cout << v[i] << ((i==N-1)?"":d);} cout<<'\n';}
template<class T> inline void coutv(deque<T> &v, string d=" "){
	ll N=(ll)v.size(); REP(i,N){cout << v[i] << ((i==N-1)?"":d);} cout<<'\n';}
template<class T> void bye(T a){cout << a << '\n'; exit(0);}
#if defined(_DEBUG)
ll dumpW = 5;
template<class T> void dump(vector<T> &v){
	REP(i, (ll)v.size()) { cerr << ((i==0)?"[":" ") << setw(dumpW) << v[i]; }  cerr << "]";
}
void dump(vll &v){
	REP(i, (ll)v.size()) {
		cerr << ((i==0)?"[":" ") << setw(dumpW);
		if       (v[i] == INF) cerr << "INF";
		else if (v[i] == -INF) cerr << "-INF";
		else                   cerr << v[i];
	}  cerr << "]";
}
template<class T> void dump(vector<vector<T>> &v){
	ll N=(ll)v.size();  string d[2][2]={{" ", "["},  {"\n", "]\n"}};
	REP(i, N) { cerr << d[0][i==0];  dump(v[i]);  cerr << d[1][i==N-1]; }
}
template<class T> void dump(vector<vector<vector<T>>> &v){
	ll N=(ll)v.size();  string d[2]={"  <", "[ <"};
	REP(i, N) { cerr << d[i==0] << i << ">\n"; dump(v[i]); }  cerr << "]\n";
}
template<class T> void dump(vector<vector<vector<vector<T>>>> &v){
	ll N=(ll)v.size();  string d[2]={"  ---<", "[ ---<"};
	REP(i, N) { cerr << d[i==0] << i << ">---\n"; dump(v[i]); }  cerr << "]\n";
}
template<class T> void dump(vector<vector<vector<vector<vector<T>>>>> &v){
	ll N=(ll)v.size();  string d[2]={"  ======<", "[ ======<"};
	REP(i, N) { cerr << d[i==0] << i << ">======\n"; dump(v[i]); }  cerr << "]\n";
}
template<class T, class S> void dump(map<T, S> &m){
	for(auto e: m) cout << e.first << " : " << e.second << '\n';
}
#else
template<class T> void dump(vector<T> &v){}
template<class T> void dump(vector<vector<T>> &v){}
template<class T> void dump(vector<vector<vector<T>>> &v){}
template<class T> void dump(vector<vector<vector<vector<T>>>> &v){}
template<class T> void dump(vector<vector<vector<vector<vector<T>>>>> &v){}
#endif

template<ll MOD> struct mll_{
	ll val;
	mll_(ll v = 0): val(v % MOD){ if (val < 0) val += MOD; }
	mll_ operator - () const { return -val; }
	mll_ operator + (const mll_ &b) const { return val + b.val; }
	mll_ operator - (const mll_ &b) const { return val - b.val; }
	mll_ operator * (const mll_ &b) const { return val * b.val; }
	mll_ operator / (const mll_ &b) const { return mll_(*this) /= b; }
	mll_ operator + (ll b) const { return *this + mll_(b); }
	mll_ operator - (ll b) const { return *this - mll_(b); }
	mll_ operator * (ll b) const { return *this * mll_(b); }
	friend mll_ operator + (ll a, const mll_ &b) { return b + a; }
	friend mll_ operator - (ll a, const mll_ &b) { return -b + a; }
	friend mll_ operator * (ll a, const mll_ &b) { return b * a; }
	friend mll_ operator / (ll a, const mll_ &b) { return mll_(a)/b; }
	mll_ &operator += (const mll_ &b) { val=(val+b.val)%MOD; return *this; }
	mll_ &operator -= (const mll_ &b) { val=(val+MOD-b.val)%MOD; return *this; }
	mll_ &operator *= (const mll_ &b) { val=(val*b.val)%MOD; return *this; }
	mll_ &operator /= (const mll_ &b) {
		ll c=b.val, d=MOD, u=1, v=0;
		while (d){
			ll t = c / d;
			c -= t * d; swap(c, d);
			u -= t * v; swap(u, v);
		}
		val = val * u % MOD;
		if (val < 0) val += MOD;
		return *this;
	}
	mll_ &operator += (ll b) { return *this += mll_(b); }
	mll_ &operator -= (ll b) { return *this -= mll_(b); }
	mll_ &operator *= (ll b) { return *this *= mll_(b); }
	mll_ &operator /= (ll b) { return *this /= mll_(b); }
	bool operator == (const mll_ &b) { return val == b.val; }
	bool operator != (const mll_ &b) { return val != b.val; }
	bool operator == (ll b) { return *this == mll_(b); }
	bool operator != (ll b) { return *this != mll_(b); }
	friend bool operator == (ll a, const mll_ &b) { return mll_(a) == b.val; }
	friend bool operator != (ll a, const mll_ &b) { return mll_(a) != b.val; }
	friend ostream &operator << (ostream &os, const mll_ &a) { return os << a.val; }
	friend istream &operator >> (istream &is, mll_ &a) { return is >> a.val; }
	static mll_ Combination(ll a, ll b){
		chmin(b, a-b);
		if (b<0) return mll_(0);
		mll_ c = 1;
		REP(i, b) c *= a-i;
		REP(i, b) c /= i+1;
		return c;
	}
};
using mll = mll_<1000000007LL>; //1000000007LL;// 998244353LL;
using vmll = std::vector<mll>;
using vvmll = std::vector<vmll>;
using vvvmll = std::vector<vvmll>;
using vvvvmll = std::vector<vvvmll>;
using vvvvvmll = std::vector<vvvvmll>;

//pairの四則演算テンプレート
template<class T,class S> inline pair<T,S>& operator+=(pair<T,S> &a, const pair<T,S> &b){ a.first+=b.first; a.second+=b.second; return a; }
template<class T,class S> inline pair<T,S>& operator-=(pair<T,S> &a, const pair<T,S> &b){ a.first-=b.first; a.second-=b.second; return a; }
template<class T,class S> inline pair<T,S>& operator*=(pair<T,S> &a, const pair<T,S> &b){ a.first*=b.first; a.second*=b.second; return a; }
template<class T,class S> inline pair<T,S>& operator/=(pair<T,S> &a, const pair<T,S> &b){ a.first/=b.first; a.second/=b.second; return a; }
template<class T,class S> inline pair<T,S>& operator%=(pair<T,S> &a, const pair<T,S> &b){ a.first%=b.first; a.second%=b.second; return a; }
template<class T,class S,class R> inline pair<T,S>& operator+=(pair<T,S> &a, R b){ a.first+=b; a.second+=b; return a; }
template<class T,class S,class R> inline pair<T,S>& operator-=(pair<T,S> &a, R b){ a.first-=b; a.second-=b; return a; }
template<class T,class S,class R> inline pair<T,S>& operator*=(pair<T,S> &a, R b){ a.first*=b; a.second*=b; return a; }
template<class T,class S,class R> inline pair<T,S>& operator/=(pair<T,S> &a, R b){ a.first/=b; a.second/=b; return a; }
template<class T,class S,class R> inline pair<T,S>& operator%=(pair<T,S> &a, R b){ a.first%=b; a.second%=b; return a; }
template<class T, class S> inline ostream &operator<<(ostream &os, const pair<T,S> &a){ return os << a.first << ' ' << a.second; }
//vectorの四則演算テンプレート
template<class T> inline vector<T>& operator+=(vector<T> &a, const vector<T> &b){ for (ll i=0; i<(ll)a.size(); i++) a[i]+=b[i];  return a; }
template<class T> inline vector<T>& operator-=(vector<T> &a, const vector<T> &b){ for (ll i=0; i<(ll)a.size(); i++) a[i]-=b[i];  return a; }
template<class T> inline vector<T>& operator*=(vector<T> &a, const vector<T> &b){ for (ll i=0; i<(ll)a.size(); i++) a[i]*=b[i];  return a; }
template<class T> inline vector<T>& operator/=(vector<T> &a, const vector<T> &b){ for (ll i=0; i<(ll)a.size(); i++) a[i]/=b[i];  return a; }
template<class T> inline vector<T>& operator%=(vector<T> &a, const vector<T> &b){ for (ll i=0; i<(ll)a.size(); i++) a[i]%=b[i];  return a; }
template<class T,class S> inline vector<T>& operator+=(vector<T> &a, S b){ for (T &e: a) e+=b;  return a; }
template<class T,class S> inline vector<T>& operator-=(vector<T> &a, S b){ for (T &e: a) e-=b;  return a; }
template<class T,class S> inline vector<T>& operator*=(vector<T> &a, S b){ for (T &e: a) e*=b;  return a; }
template<class T,class S> inline vector<T>& operator/=(vector<T> &a, S b){ for (T &e: a) e/=b;  return a; }
template<class T,class S> inline vector<T>& operator%=(vector<T> &a, S b){ for (T &e: a) e%=b;  return a; }

template <class T, class E> struct LazySegmentTree{
	using F = function<T(T, T)>;
	using G = function<T(T, E)>;
	using H = function<E(E, E)>;
	F f; //!< データ同士の合成関数
	G g; //!< 作用関数
	H h; //!< 作用素同士の合成関数
	T ti; //!< データの単位元 実際の単位元をセットしないとだめ
	E ei; //!< 作用素の単位元 実際の単位元ではなくても、使わない値ならOK
	ll n=1; //!< データ数の2べき上界
	vector<T> dat;
	vector<E> laz;
	LazySegmentTree() {}
	LazySegmentTree(vector<T> &v, F f, G g, H h, T ti, E ei) { Init(v, f, g, h, ti, ei); }
	void Init(vector<T> &v, F f, G g, H h, T ti, E ei){
		this->f=f; this->g=g; this->h=h; this->ti=ti; this->ei=ei;
		while (n<(ll)v.size()) n<<=1;
		dat.resize(2*n-1, ti);
		laz.resize(2*n-1, ei);
		for (ll i=0; i<(ll)v.size(); i++) dat[n-1+i] = v[i];
		for (ll i=n-2; i>=0; i--) dat[i] = f(dat[2*i+1], dat[2*i+2]);
	}
	void Update(ll a, ll b, E x){ update(a, b+1, x, 0, 0, n); } //[a,b]にxを作用
	void update(ll a, ll b, E x, ll k, ll l, ll r){ //注目ノードk=[l,r)
		if (r<=a || b<=l) eval(k); //[l,r)が[a,b)と重ならない時
		else if (a<=l && r<=b){ //[l,r)が[a,b)の内側の時
			laz[k] = h(laz[k], x);
			eval(k); //親ノードが後でdat[k]を見るため、ここで評価しておく必要あり
		}
		else { //[l,r)が[a,b)から一部はみ出す時
			eval(k); //子ノードを処理する前に評価しておく必要あり
			update(a, b, x, k*2+1, l, (l+r)/2);
			update(a, b, x, k*2+2, (l+r)/2, r);
			dat[k] = f(dat[k*2+1], dat[k*2+2]);
		}
	}
	T Range(ll a, ll b) { return range(a, b+1, 0, 0, n); }//[a,b]の値を取得
	T range(ll a, ll b, ll k, ll l, ll r){ //注目ノードk=[l,r)
		if (r<=a || b<=l) return ti; //[l,r)が[a,b)と重ならない時
		eval(k); //自分や子の値を見る前に評価が必要
		if (a<=l && r<=b) return dat[k];//[l,r)が[a,b)の内側の時
		return f(range(a, b, k*2+1, l, (l+r)/2), range(a, b, k*2+2, (l+r)/2, r));
		//[l,r)が[a,b)から一部はみ出す時
	}
	ll FindL(ll a, ll b, T x) { return findL(a, b+1, x, 0, 0, n); }
	ll findL(ll a, ll b, T x, ll k, ll l, ll r){ //[l,r)内最左 なければb
		if (r<=a || b<=l) return b; //範囲外
		eval(k);
		if (f(dat[k], x) != dat[k]) return b; //条件を満たさない
		if (n-1 <= k) return k-(n-1); //葉なら見つかった→位置return
		ll        i = findL(a, b, x, 2*k+1, l, (l+r)/2); //左部分木探す
		if (i==b) i = findL(a, b, x, 2*k+2, (l+r)/2, r); //左になければ右
		return i;
	}
	ll FindR(ll a, ll b, T x) { return findR(a, b+1, x, 0, 0, n); }
	ll findR(ll a, ll b, T x, ll k, ll l, ll r){ //[l,r)内最右 なければa-1
		if (r<=a || b<=l) return a-1; //範囲外
		eval(k);
		if (f(dat[k], x) != dat[k]) return a-1; //条件を満たさない
		if (n-1 <= k) return k-(n-1); //葉なら見つかった→位置return
		ll          i = findR(a, b, x, 2*k+2, (l+r)/2, r); //右部分木探す
		if (i==a-1) i = findR(a, b, x, 2*k+1, l, (l+r)/2); //右になければ左
		return i;
	}
	void eval(ll k){
		if (laz[k] == ei) return;
		if (k<=n-2){ //子に作用素を配る
			laz[k*2+1] = h(laz[k*2+1], laz[k]);
			laz[k*2+2] = h(laz[k*2+2], laz[k]);
		}
		//自分に作用させる
		dat[k] = g(dat[k], laz[k]);
		laz[k] = ei;
	}
	void Dump(ll w=5){
		auto disp=[&](ll x){
			if (x==-INF) cerr << setw(w) << "-INF";
			else if (x== INF) cerr << setw(w) << "INF";
			else              cerr << setw(w) << x;
		};
		REP(i, n) for (ll k=i+n-1, m=1, p=1; k>=0; p=m, m*=k%2, k=(k==0)?-1:(k-1)/2){
			if (m){
				cerr << ((k<n-1)?" ┬ ":""); disp(dat[k]); cerr<<" /"; disp(laz[k]);
			}
			else{
				cerr << ((p&~m) ?" ┘ ":"");
			}
			if (k==0) cerr << '\n';
		} cerr << '\n';
	}
};


void solve()
{
	ll h, w;  cin >> h >> w;
	vector<pair<ll, ll>> ab = cinv2<ll, ll>(h);
	ab-=1;

	vll ini(w);

	LazySegmentTree<ll, ll> sgt(
		ini,
		[](ll x, ll y){ return min(x, y); },//データ同士の合成関数
		[](ll x, ll y){ return y; },//データxに作用素yを作用させる関数
		[](ll x, ll y){ return y; },//作用素の合成関数
		INF, //データの単位元 実際の単位元をセットしないとだめ
		-INF); //作用素の単位元 実際の単位元ではなくても、使わない値ならOK

	vll ans(h);
	rep(i, 0, h-1){
		ll a,b;  tie(a,b) = ab[i];
		ll bb=b+1;
		//スライダー処理
		if (bb<w){
			ll q=sgt.Range(b+1, b+1);
			if (q==INF){
				ll loc = sgt.FindR(a,b,INF-1);//[a,b]内最右の、x以下の位置
				if (loc!=a-1){//それが存在したら
					ll dif=bb-loc;
					ll v=sgt.Range(loc, loc);
					ll vv=v+dif;
					sgt.Update(bb, bb, vv);
				}
			}
		}
		
		sgt.Update(a, b, INF);

		ll mn=sgt.Range(0, w-1);
		if (mn==INF){
			//以降全部-1
			rep(k, i, h-1){
				ans[k]=-1;
			}
			break;
		}
		ans[i]=mn+i+1;
	}
	coutv(ans, "\n");

}


int main(){
#if 1
	solve();
#else
	ll t;  cin >> t;
	rep(i, 0, t-1){
		solve();
	}
#endif
	return 0;
}


Measured memory_bytes: 17708