> #include <iostream>
> using namespace std;
> int main()
> {
> 	int N,i,j,f[210],begin,end,T,max,tem;
> 	cin>>T;
> 	while(T--)
> 	{
> 		max = -1;
> 		memset(f,0,sizeof(f));
> 		cin>>N;
> 		for(i = 1; i<=N ;i++)
> 		{
> 			cin>>begin>>end;
> 			if(begin > end)//保证开始<结束
> 			{
> 				tem = begin ;
> 				begin =end;
> 				end = tem ;
> 			}
> 			for(j = (begin+1)/2; j<=(end+1)/2; j++)
> 			{
> 				f[j]++;
> 				if(f[j]>max)
> 					max = f[j];
> 			}
> 		}
> 		cout<<max*10<<endl;
> 	}
> 
> 	return 0;
> }