#include <bits/stdc++.h>

using namespace std;

typedef long long int64;

int main()
{
  int64 D, Q, A[30000], B[30000];
  vector< int64 > nums;
  int64 touch[600000] = {};


  scanf("%lld %lld", &D, &Q);
  for(int i = 0; i < Q; i++) {
    scanf("%lld %lld", &A[i], &B[i]);
    nums.push_back(A[i] - 1);
    nums.push_back(A[i]);
    nums.push_back(B[i]);
    nums.push_back(B[i] + 1);
  }

  sort(begin(nums), end(nums));
  nums.erase(unique(begin(nums), end(nums)), end(nums));

  for(int i = 0; i < Q; i++) {
    A[i] = lower_bound(begin(nums), end(nums), A[i]) - begin(nums);
    B[i] = lower_bound(begin(nums), end(nums), B[i]) - begin(nums);
  }

  int64 ret = 0;
  for(int i = 0; i < Q; i++) {
    for(int64 j = 0; j < nums.size(); j++) {
      if(A[i] <= j && j <= B[i]) touch[j] = true;
    }
    int64 last = -1;
    for(int64 j = 0; j < nums.size(); j++) {
      if(!touch[j]) {
        last = -1;
      } else {
        if(last < 0) last = j;
        ret = max(ret, nums[j] - nums[last] + 1);
      }
    }
    printf("%lld\n", ret);
  }
}