#include <fstream>
#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
using namespace std;
ifstream fin("loverfinding.in");
ofstream fout("loverfinding.out");
int n,x0,y0,xt,yt;
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
int main(int argc, char** argv) 
{
	int x,y;
	fin>>n>>x0>>y0>>xt>>yt;
	if(x0==xt&&y0==yt)
	{
		fout<<"0"<<endl;
		return 0;
	}
	for(int i=1;i<=n;i++)
	{
		fin>>x>>y;
		x0+=x,y0+=y;
		if(x0==xt&&y0==yt)
		{
			fout<<i<<endl;
			return 0;
		}
	}
	fin.close();
	fout.close();
	return 0;
}