#include <iostream>
using namespace std;
bool can(int v, int x, int stop)
{
int tram_time = stop / v;
int petro_time = abs(x - stop);
return tram_time >= petro_time;
}
int main()
{
int v, x, a, b;
cin >> v >> x >> a >> b;
bool can_first = can(v, x, a);
bool can_second = can(v, x, b);
if(can_first && can_second)
{
if(abs(x - a) <= abs(x - b))
{
cout << "1" << endl;
}
else
{
cout << "2" << endl;
}
}
else if(can_first || can_second)
{
if(can_first)
{
cout << "1" << endl;
}
else
{
cout << "2" << endl;
}
}
else
{
cout << "-1" << endl;
}
return 0;
}