#include <iostream>
#include <string>
using namespace std;

int n;
long long int x, y;
long long int m;
long long int cnt = 1;
long long int temp = 1;
int main()
{
cin >> n;

for (int i = 1; i <= n; i++)
{
cin >> x >> y;

m = y - x;

while (m > temp)
{
temp += cnt++;

//cout << "m-- " << m << "temp-- " << temp << " cnt-- " << cnt << endl;
}

cout << cnt << endl;
cnt = 1;
temp = 1;
}

}