#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < n; i++)
#define repb(i, a, b) for(int i = a; i >= b; i--)
#define all(a) a.begin(), a.end()
#define int long long
#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
using namespace std;
typedef pair<int, int> P;
const int mod = 1000000007;
const int INF = 2e18;

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int d, q, ret = 0;
    cin >> d >> q;
    set<P> st;
    st.emplace(-INF, -INF);
    st.emplace(INF, INF);
    rep(i, 0, q){
        int a, b;
        cin >> a >> b;
        st.emplace(a, b);
        auto p = --st.lower_bound({a, -1});
        if(a - 1 <= p -> second) a = p -> first;
        else ++p;
        while(b + 1 >= p -> first){
            b = max(b, p->second);
            p = st.erase(p);
        }
        st.emplace(a, b);
        ret = max(ret, b - a + 1);
        cout << ret << endl;
    }
}