#include <iostream>
#include <vector>
#include <climits>
#include <cmath>

#define vpii vector<pair<int,int> >
#define vvi vector<vector<int> >

using namespace std;


int main() {
	ios::sync_with_stdio(false);
	int N;
	cin >> N;		
	for(int NI = 0; NI < N; ++NI) {		
		int K;
		cin >> K;

		vector<pair<int,int> > prev;
		prev.resize(K + 1);

		for(int KI = 0; KI < K; ++KI) {
			int l, r;
			cin >> l >> r;
			
			prev[KI] = make_pair(l,r);
		}

		int min = INT_MAX;
		for(int i = 0; i < K; ++i) {
			for(int j = 0; j < K; ++j) {
				int m = prev[j].second - prev[i].first;
				m += abs(i - j);
				if (m < min) min = m;
			}
		}
	
	
		cout << "K prechodu reky je treba " << min << " pontonu." << endl;
	}

	return 0;
}