/* @judge_id: 1705PZ 10228 C */
#include <stdio.h>
#include <math.h>

main()
{
	int i, m, n;
	float a[100][2], sum, sx, sy;
	scanf("%d", &m);
	while(m--) {
		scanf("%d", &n);
		sx = sy = 0;
		for(i = 0; i < n; i++) {
			scanf("%f %f", &a[i][0], &a[i][1]);
			sx += a[i][0];
			sy += a[i][1];
		}
		sum = 0;
		sx = floor(sx / n + 0.5);
		sy = floor(sy / n + 0.5);
		for(i = 0; i < n; i++) {
			sum += pow(pow(a[i][0] - sx, 2) + pow(a[i][1] - sy, 2), 0.5);
		}
		printf("%.0f\n", sum);

	}
}