#include<iostream>

#include<cstdio>

#include<cstring>

#include<algorithm>

using namespace std;

struct Node

{

    int s,t;

    int p;

} a[210];

bool cmp(Node a, Node b)

{

    return a.t < b.t;

}

int main()

{

    int t,n,i,j,tim,ma;

    scanf("%d",&t);

    while(t--)

    {

        scanf("%d",&n);

        for(i = 0; i < n; i++)

        {

            a[i].p = 0;

            scanf("%d%d",&a[i].s,&a[i].t);

            a[i].s = (a[i].s + 1) / 2;  //处理奇偶公用一个走量的情况(这个一直没考虑，所以WA)

            a[i].t = (a[i].t + 1) / 2;

            if(a[i].s > a[i].t)  //保证 s < t

            {

                j = a[i].s;

                a[i].s = a[i].t;

                a[i].t = j;

            }

        }

        sort(a,a+n,cmp);

        ma = 0;

        for(i = 0; i < n; i++)

        {

            tim = 1;

            for(j = i+1; j < n; j++)

            {

                if(a[j].s <= a[i].t)//判断是否有重叠

                {

                    tim++;  //增加一个重叠

                }

            }

            if(tim > ma)

            {

                ma = tim;

            }

        }

        printf("%d\n",ma*10);

    }

    return 0;

}