#include <cstdio>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;

int getmin(int a, int b)
{
  if (a < b)
  {
    return a;
  }
  return b;
}
int main()
{
  int testCases;
  scanf ("%d", &testCases);
  for (int tc = 0; tc < testCases; tc++)
	{
		int height;
		int previousLineCost = 1147483648;
		int previousLineLeft = -1;
		
		int fromRightCost = 1147483648;
		int previousLineRight = -1;
		
		
		int bestCost = 1147483648;
		scanf("%d", &height);
		for (int i = 0; i < height; i++)
		{
		  int left, right;
		  scanf("%d %d", &left, &right);
		  int horizontally = right - left;
		  int verticallyByLeft = 1147483648;
		  int verticallyByRight = 1147483648;
		  if (previousLineLeft != -1)
		  {
		    verticallyByLeft = (previousLineLeft - left) + 1 + previousLineCost;
		  }
		  if (previousLineRight != -1)
		  {
		    verticallyByRight = (right - previousLineRight) + 1 + fromRightCost;
		  }
		  previousLineCost = getmin(horizontally, verticallyByLeft);	
		  fromRightCost = getmin(horizontally, verticallyByRight);
		  previousLineLeft = left;
		  previousLineRight = right;
		  if (previousLineCost < bestCost)
		  {
		   bestCost = previousLineCost;
		  }
		  if (fromRightCost < bestCost)
		  {
		   bestCost = fromRightCost;
		  }		  
		}
		printf("K prechodu reky je treba %d pontonu.\n", bestCost);
	}
}