#include <bits/stdc++.h>

using namespace std;

typedef long long int64;
const int64 INF = 1LL << 60;

int main()
{
  int64 D, Q, ret = 0;

  cin >> D >> Q;

  set< pair< int64, int64 > > st;
  st.emplace(-INF, -INF);
  st.emplace(INF, INF);

  for(int i = 0; i < Q; i++) {
    int64 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;
  }
}