#include <iostream>
#include <fstream>
using namespace std;
int next (int k, int n, int c[]) {
	if (k == n+1) return k;
	for (int i=k+1; i <= n+1; i++) {
		if (c[i] == 1)
			return i;
	}
	return 0;
}
int main()
{
	int t, n, i, j, tom, jack, count, current;
	int a[210], b[210], c[210];
	ifstream in("fu.txt");

	in >> t;
	while (t--) {
		in >> n;
		count=0;
		for (i=1; i <= n; i++) {
			in >> tom >> jack;
			if (tom > jack)
				swap (tom, jack);
			if (tom%2 == 0) tom--;
			if (jack%2 == 1) jack++;
			a[i] = tom;
			b[i] = jack;
			c[i] = 1;
		}
		a[n+1] = 410;
		b[n+1] = 440;
		c[n+1] = 1;

		for (i=2; i <= n; i++) {
			for (j=i; j>1 && b[j]<b[j-1]; j--) {
				swap(b[j], b[j-1]);
				swap(a[j], a[j-1]);
			}
		}

		current=1;
		while (current != n+1) {
			for (i=next(current, n, c); current != n+1; i=next(i, n, c)) {
				if (a[i] > b[current]) {
					c[current] = 0;
					current = i;
				}
			}
			count++;
			for (i=1; i <= n+1; i++) {
				if (c[i] == 1) {
					current = i;
					break;
				}
			}
		}
		printf("%d\n", count*10);
	}
	return 0;
}