#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]);
    nums.push_back(B[i]);
  }

  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 = A[i]; j <= B[i]; j++) touch[j] = true;
    int64 latte = A[i], malta = B[i];
    while(latte >= 0 && touch[latte]) --latte;
    while(malta < nums.size() && touch[malta]) ++malta;
    ret = max(ret, nums[malta - 1] - nums[latte + 1] + 1);
    printf("%lld\n", ret);
  }
}