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

using namespace std;

int calculateMin( int * startP, int * endP, int height )
{
	int min = INT_MAX;
	
	for ( int i = 0; i < height; i++ )
	{
		for ( int j = i; j < height; j++ )
		{
			int val = abs(endP[j] - startP[i]) + j - i;
			if ( val < min )
				min = val;
		}
	
	}
	
	return min;
}


int main()
{
	int cases;
	
	cin >> cases;
	
	int height = 0;
	for ( int i = 0; i < cases; i++ )
	{
		cin >> height;
		
		int * startP = new int[height];
		int * endP = new int[height];
		
		for ( int j = 0; j < height; j++ )
		{
			cin >> startP[j] >> endP[j];
		}
		
		int min = calculateMin(startP, endP, height);
		
		cout << "K prechodu reky je treba " << min << " pontonu." << endl;
		
		delete [] startP;
		delete [] endP;
	}
	
	
	
	
	
	
	
	
	return 0;
}