#include <bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define mp make_pair
typedef long long ll;
const int N=2e5+5;
const int mod=1e9+7;
const int inf=0x3f3f3f3f;
const ll INF=1e18+3;
#define DEBUG 
#ifdef DEBUG
#define debug(x...) cerr<<"["#x"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(x)
#else
#define debug(...) {}
#endif
//debug(n,m);debug("a,b");
//double max:0x7f,0x43 min:0xfe 0x c2  int:0x3f 
//运算符 priority  后缀 前缀 */+- 位移 比较 &^| && || 赋值
ll get_ans(ll n,ll k){
  ll beg=floor(sqrt(n*2.0)+1.5);
  ll l=beg,r=2e9;
  while(l<=r){
    ll mid=l+r>>1;
    if(n+(beg+mid)*(mid-beg+1)/2>=k) {
      r=mid-1;
    }else l=mid+1;
  }
  //cout<<beg<<' '<<l<<"  -- "<<r<<'\n';
  return (l-beg+1)+n+(beg+l)*(l-beg+1)/2-k;

}
void solve()
{
    ll n,k;
    cin>>n>>k;
    if(n>=k) {
      cout<<n-k<<'\n';
      return;
    }
    ll res,t=floor(sqrt(n*2.0)+1.5);
    res=floor((t-1.5) * (t-1.5)/2);
    while(floor(sqrt(res*2.0)+1.5)>=t) res--;
    while(floor(sqrt(res*2.0)+1.5)<t) res++;
    res--;
    cout<<min(get_ans(n,k),n-res+get_ans(res,k))<<"\n";


    return;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  #if 1 
        int T; cin>>T; while(T--) solve();
    #else 
        solve();
    #endif 
  return 0; 
}