#include <stdio.h>
#include <math.h>

double dist(int m);

const int MAX_N = 100;
const int MIN_X = 0;
const int MAX_X = 10000;

struct
{
	int x;
	int y;
} arr[MAX_N];

int n, minX, maxX;

int main()
{
	int i, l, r, m;
	//freopen("test.in", "r", stdin);
	//freopen("test.out", "w", stdout);
	l = sizeof(int);
	while(1)
	{
		scanf("%d", &n);
		if(n==0) break;
		minX = MAX_X;
		maxX = MIN_X;
		for(i=0; i<n; i++)
		{
			scanf("%d%d", &arr[i].x, &arr[i].y);
			if(arr[i].x < minX) minX = arr[i].x;
			if(arr[i].x > maxX) maxX = arr[i].x;
		}
		if(minX == maxX)
		{
			printf("%d\n", arr[0].x);
			continue;
		}
		l = minX;
		r = maxX;
		while(l<r)
		{
			m = (l+r)/2;
			if(dist(m) > dist(m+1))
			{
				l=m+1;
			}
			else
			{
				r=m;
			}
		}
		printf("%d\n", l);
	}
	return 0;
}

double dist(int m)
{
	int i;
	double sum = 0;
	for(i=0; i<n; i++)
	{
		sum += sqrt((double)((arr[i].x-m)*(arr[i].x-m) + arr[i].y*arr[i].y));
	}
	return sum;
}