http://acm.hdu.edu.cn/showproblem.php?pid=1050
/*
2011-9-8
author:BearFly1990
*/
package acm.hdu.tests;
import java.io.BufferedInputStream;
import java.util.Arrays;
import java.util.Scanner;
public class HDU_1050 {
public static void main(String[] args) {
Scanner in = new Scanner(new BufferedInputStream(System.in));
int t = 0;
int n = 0;
int x,y,max;
int[] a = new int[200];
t = in.nextInt();
while(t-- > 0){
max = -1;
n = in.nextInt();
Arrays.fill(a, 0);
for(int i = 0; i < n; i ++){
x = in.nextInt();
y = in.nextInt();
x = (x - 1) / 2;
y = (y - 1) / 2;
if(x > y){
int temp = x;
x = y;
y = temp;
}
for(int k = x; k <=y; k++){
a[k]++;
if(a[k] > max){
max = a[k];
}
}
}
System.out.printf("%d\r\n",max*10);
}
}
}