1083(Greedy)

#include <iostream>
using namespace std;

class intv{
public:
	int start;
	int end;
	intv(): start(0), end(0){}
	intv(int s, int e): start(s) , end(e){}
};



int main() {
	int cases;
	cin >> cases;
	for(int ii = 0; ii < cases; ii++){
		int N;
		intv vss[200];
		cin >> N;
		for(int i = 0; i < N; i++){
			cin >> vss[i].start >> vss[i].end;
			if(vss[i].start > vss[i].end){
				int temp = vss[i].start;
				vss[i].start = vss[i].end;
				vss[i].end = temp;
			}
		}
		quickSort(vss, 0, N-1);
		for(int i = 0; i < N; i++){
			vss[i].start -=1;
			vss[i].start /=2;
			vss[i].end -=1;
			vss[i].end /=2;
		}
		bool state[200] = {false};
		int remain = N;
		int cnt = 0;
		while(remain > 0){
			int place = -1;
			int idx = -1;
			while(idx < N-1){
				idx++;
				if(state[idx] || vss[idx].start <= place){
					//idx++;
					continue;
				}
				state[idx] = true;
				remain--;
				place = vss[idx].end;
			}
			cnt++;
		}
		cout << cnt * 10 << endl;
	}
	//cout << "!!!Hello World!!!" << endl; // prints !!!Hello World!!!
	return 0;
}