RANKLIST

#include <iostream>

using namespace std;

long long sums[150000];

int bsearch(long long sum,int n)
{
    long long lo=1;
    long long hi=141420;
    long long mid;
    while(lo<hi)
    {
        mid=lo+(hi-lo)/2;
        if(sums[mid]+(n-mid)<=sum)
            lo=mid+1;
        else
            hi=mid;
    }
    return lo-1;
}

int main()
{
    sums[0]=0;
    int counter=1;
    for(long long j=1;j<150000;j++)
        sums[j]=sums[j-1]+j;

    int t;
    cin>>t;

    while(t--)
    {
        long long s;
        int n;
        cin>>n>>s;
        cout<<n-bsearch(s,n)<<endl;
    }
    return 0;
}