#include <iostream>
#include <cstdio>

using namespace std;

int main()
{
    int N,X,Y;
    cin >> N;

    for(int i = 1;i <= N;i ++)
    {
        cin >> X >> Y;
        if(X > Y) swap(X,Y);
        int sum = 0;
        for(int j = X+1;j<Y;j++)
        {
            if(j%2 == 1 || j%2 == -1) sum += j;      // 注意负奇数不要落下
        }
        cout << sum << endl;
    }

}