#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
using namespace std;
#define INF 2000000000
#define MAX
typedef long long ll;
const double pi=acos (-1.0);
const double eps=1e-8 ;
const int inf=0x3f3f3f3f ;
int n,T;
vector l[1440];
vector c[1440];
int sum,m;
int change(char ttt[])
{
int time = 0;
time += (int)ttt[4]-'0';
time += (int)(ttt[3] - '0')*10;
time += (int)(ttt[1]-'0')*60;
time += (int)(ttt[0]-'0')*600;
return time;
}
int main()
{
int i,j;
scanf("%d",&T);
while(T--)
{
for(i=0;i<1440;i++)
{
l[i].clear();
c[i].clear();
}
sum = 0;
m = 0;
scanf("%d",&n);
int temp;
char cc[10];
char tt[10];
for(i=0;i
