1691. Abundance

water.

#include <iostream>
using namespace std;

int main()
{
	int t,x,y;
	cin>>t;
	while(t--)
	{
		cin>>x>>y;
		int result=-999999;
		bool b=false;
		for(int i=y;i>=x;i--)
		{
			int temp=0,ti=i,j=1;
			for(int j=1;j*j<=i;j++)
			{
				if(i%j==0)
				{
					temp+=j;
					if(j*j!=i)
						temp+=i/j;
				}
			}
			temp-=2*i;
			if(temp>0) 
			{
				b=true;
				if(temp>result)
					result=temp;
			}
		}
		if(!b) cout<<-1<<endl;
		else cout<<result<<endl;
	}
	return 0;
}