#line 1 "a.cpp"
#include <iostream>
#include <algorithm>
#include <utility>
#include <string>
#include <vector>
#include <set>
#include <stack>
#include <queue>
#include <map>
#include <math.h>
#include <string.h>
#include <iomanip>
#include <numeric>
#include <cstdlib>
#include <cstdint>
#include <cmath>
#include <functional>
#include <limits>
#include <cassert>
#include <bitset>
#include <chrono>
#include <random>
#include <memory>
 
/* macro */
 
#define rep(i, a, n) for (int i = (int)(a); i < (int)(n); i++)
#define rrep(i, a, n) for (int i = ((int)(n-1)); i >= (int)(a); i--)
#define Rep(i, a, n) for (i64 i = (i64)(a); i< (i64)(n); i++)
#define RRep(i, a, n) for (i64 i = ((i64)(n-i64(1))); i>=(i64)(a); i--)
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define Bit(n) (1LL<<(n))
 
/* macro end */
 
/* template */
 
namespace ebi {
 
#ifdef LOCAL
#define debug(...)                                                    \
    std::cerr << "LINE: " << __LINE__ << "  [" << #__VA_ARGS__ << "]:", \
        debug_out(__VA_ARGS__)
#else
#define debug(...)
#endif
 
void debug_out() { std::cerr << std::endl; }
 
template <typename Head, typename... Tail>
void debug_out(Head h, Tail... t) {
    std::cerr << " " << h;
    if (sizeof...(t) > 0) std::cout << " :";
    debug_out(t...);
}
 
template <typename T1, typename T2>
std::ostream& operator<<(std::ostream& os, std::pair<T1, T2> pa) {
    return os << pa.first << " " << pa.second;
}
 
template <typename T>
std::ostream& operator<<(std::ostream& os, std::vector<T> vec) {
    for (std::size_t i = 0; i < vec.size(); i++) os << vec[i] << (i + 1 == vec.size() ? "" : " ");
    return os;
}
 
using size_t = std::size_t;
using i64 = std::int64_t;
using u64 = std::uint64_t;
using ld = long double;
 
template<class T> void fill(std::vector<T> &v) { for(T &e: v) std::cin >> e; }
 
template <class T>
inline bool chmin(T &a, T b) {
    if (a > b){
        a = b;
        return true;
    }
    return false;
}
 
template <class T>
inline bool chmax(T &a, T b) {
    if (a < b){
        a = b;
        return true;
    }
    return false;
}
 
template <class T>
T gcd(T a, T b){
    if( b==0 ) return a;
    else return gcd(b, a%b);
}
 
template <class T>
T lcm(T a, T b) {
    a /= gcd(a, b);
    return a*b;
}
 
template<class T>
T Pow(T x, i64 n) {
    T res = 1;
    while(n>0){
        if(n&1) res = res *x;
        x = x*x;
        n>>=1;
    }
    return res;
}
 
template<class T>
T scan() {
    T val;
    std::cin >> val;
    return val;
}
 
constexpr i64 LNF = std::numeric_limits<i64>::max()/4;
 
constexpr int INF = std::numeric_limits<int>::max()/2;
 
const std::vector<int> dy = {1,0,-1,0,1,1,-1,-1};
const std::vector<int> dx = {0,1,0,-1,1,-1,1,-1};
 
}
 
/* template end */

#line 2 "data_structure/section_set.hpp"

#line 6 "data_structure/section_set.hpp"

namespace ebi {

template<class T>
struct section_set {
private:
    std::set<std::pair<T,T>> set;
public:
    section_set() {
        set.insert({std::numeric_limits<T>::min(), std::numeric_limits<T>::min()});
        set.insert({std::numeric_limits<T>::max(), std::numeric_limits<T>::max()});
    }

    // [l, r)を追加
    void insert(T l, T r) {
        auto itr = std::prev(set.lower_bound({l, std::numeric_limits<T>::min()}));
        if(l <= itr->second) {
            assert(itr->first <= l);
            l = itr->first;
            r = std::max(r, itr->second);
            set.erase(itr);
        }
        itr = set.lower_bound({l, -1});
        while(itr->first <= r) {
            assert(l <= itr->first);
            r = std::max(r, itr->second);
            itr = set.erase(itr);
        }
        set.insert({l, r});
        return;
    }

    // 集合内の[l, r)に含まれている要素を削除
    void erase(T l, T r) {
        auto itr = std::prev(set.lower_bound({l, std::numeric_limits<T>::min()}));
        if(l < itr->second) {
            assert(itr->first < l);
            set.insert({itr->first ,l});
            if(r < itr->second) {
                set.insert({r, itr->second});
            }
            set.erase(itr);
        }
        itr = set.lower_bound({l, std::numeric_limits<T>::min()});
        while(itr->first < r) {
            if(itr->second <= r) {
                itr = set.erase(itr);
            }
            else {
                set.insert({r, itr->second});
                set.erase(itr);
                break;
            }
        }
        return;
    }

    bool find(T x) const {
        auto itr = std::prev(set.upper_bound({x, std::numeric_limits<T>::max()}));
        if(x < itr->second) {
            assert(itr->first <= x);
            return true;
        }
        else {
            return false;
        }
    }

    bool find(T l, T r) const {
        auto itr = std::prev(set.upper_bound({l, std::numeric_limits<T>::max()}));
        if(r <= itr->second) {
            assert(itr->first <= l);
            return true;
        }
        else {
            return false;
        }
    }

    std::pair<T,T> belong(T x) const {
        auto itr = std::prev(set.upper_bound({x, std::numeric_limits<T>::max()}));
        if(x <= itr->second) {
            assert(itr->first <= x);
            return *itr;
        }
        else {
            return {0, 0};
        }
    }

    std::pair<T,T> lower_bound(T l) const {
        return *set.lower_bound({l, -1});
    }
};

}
#line 136 "a.cpp"

namespace ebi {

void main_() {
    i64 d;
    int q;
    std::cin >> d >> q;
    section_set<i64> set;
    i64 ans = 0;
    while(q--) {
        i64 a,b;
        std::cin >> a >> b;
        b++;
        set.insert(a, b);
        auto [l, r] = set.belong(a);
        chmax(ans, r-l);
        std::cout << ans << '\n'; 
    }
}

}
 
int main() {
    std::cout << std::fixed << std::setprecision(15);
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);
    int t = 1;
    // std::cin >> t;
    while(t--) {
        ebi::main_();
    }
    return 0;
}