1746. DreamingAboutCarrots

#include <iostream>
using namespace std;

int main()
{
	int x1,y1,x2,y2,a,b,c,d;
	while(cin>>a>>b>>c>>d)
	{
		x1=(a<c)?a:c;
		x2=(a<c)?c:a;
		y1=(b<d)?b:d;
		y2=(b<d)?d:b;
		if(x1==x2)
		{
			if(y2-y1>1)
				cout<<y2-y1-1<<endl;
			else cout<<0<<endl;
			continue;
		}
		if(y1==y2)
		{
			if(x2-x1>1)
				cout<<x2-x1-1<<endl;
			else cout<<0<<endl;
			continue;
		}
		int count=0;
		for(int i=x1+1;i<x2;i++)
			for(int j=y1+1;j<y2;j++)
				if((double)(y2-j)/(x2-i)==(double)(j-y1)/(i-x1))
					count++;
		cout<<count<<endl;
	}
}