#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
#define rep(i, n) for(int i = 0; i < n; i++)

int main(){
    ll d; cin >> d;
    int n; cin >> n;
    set<pair<ll, ll>> st;

    ll const inf = 2e18;
    st.emplace(-inf, -inf);
    st.emplace(inf, inf);

    ll ans = 0;

    for(int i = 0; i < n; i++){
        ll x, y; cin >> x >> y;
        y++;

        auto it = st.lower_bound(pair(x, y)); it--;

        if((*it).first <= x && x <= (*it).second){
            x = min(x, (*it).first);
            y = max(y, (*it).second);
            st.erase(it);
        }

        it = st.lower_bound(pair(x, y));
        while(true){
            if(x <= (*it).first && (*it).first <= y){
                y = max(y, (*it).second);
                it = st.erase(it);
            }else{
                break;
            }
        }

        st.emplace(x, y);
        ans = max(ans, y-x);
        cout << ans << endl;
    }

}