// Codeforces.cpp : This file contains the 'main' function. Program execution begins and ends there.
//
#include <iostream>
#include <algorithm>
#include <string>
#include <map>
#include <vector>
#include <queue>
#include <stack>
#include <cmath>
using namespace std;
int main()
{
int t,l,r,L,R;
vector < pair < int, int > > v;
cin >> t;
while (t--)
{
v.clear();
cin >> l >> r >> L >> R;
v.push_back(make_pair(l, r));
v.push_back(make_pair(L, R));
sort(v.begin(), v.end());
if (v[1].first > v[0].second) {
cout << 1 << endl;
continue;
}
int locked = min(v[1].second,v[0].second) - v[1].first;
if (v[1].first > v[0].first)locked++;
if (v[0].second > v[1].second || v[0].second < v[1].second)locked++;
cout << locked << endl;
}
return 0;
}
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