points

#include<bits/stdc++.h>

using namespace std;
const int maxn = 5010;
struct seg{
    int x1 , y1 , x2 , y2 ;
    seg() {
        x1 = y1 = x2 = y2 = 0 ;
    }
    seg( int _x1 , int  _y1 , int _x2 , int _y2) {
        x1 = _x1 ;
        y1 = _y1 ;
        x2 = _x2 ;
        y2 = _y2 ;
    }
    void input () {
        cin>> x1 >> y1 >> x2 >> y2 ;
    }
};
int n;
seg p [maxn] ;
set < pair < int , int > > pst ;
void walkthrough(int x1, int y1 ,int x2 , int y2 , int dx , int dy){
    for( int x = x1, y = y1 ; x <= x2 ; x += dx , y += dy)
        pst . insert ( { x , y } ) ;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n ;
    for ( int i = 0 ; i < n ; ++ i )
        p [i] . input () ;
    for ( int i = 0 ; i < n ; ++ i ){
        if ( p [i] . x1 == p [i] . x2){
            if( p [i] . y1 < p [i] . y2)
                for ( int y = p [i] . y1 ; y <= p [i] . y2 ; ++ y)
                    pst . insert ( { p [i] . x1 , y } ) ;
            else for ( int y = p [i] . y2 ; y <= p [i] . y1 ; ++ y)
                    pst . insert ( { p [i] . x1 , y } ) ;
        }
        else if ( p [i] . y1 == p [i] . y2){
            if( p [i] . x1 < p [i] . x2)
                for ( int x = p [i] . x1 ; x <= p [i] . x2 ; ++ x)
                    pst . insert ( { x , p [i] . y1 } ) ;
            else for ( int x = p [i] . x2 ; x <= p [i] . x1 ; ++ x)
                    pst . insert ( { x , p [i] . y1 } ) ;
        }
        else{
            int difx = abs ( p [i] . x2 - p [i] . x1 ) ;
            int dify = abs ( p [i] . y2 - p [i] . y1 ) ;
            int gcd = __gcd ( difx , dify ) ;
            int dx = difx / gcd ;
            int dy = dify / gcd ;
            /*walkthrough ( min ( p [i] . x1 , p [i] . x2) , min ( p [i] . y1 , p [i] . y2 ) ,
                          max ( p [i] . x2 , p [i] . x2) , max ( p [i] . y1 , p [i] . y2 ) ,
                          dx , dy ) ;*/
            if ( p [i] . x1 < p [i] . x2){
                if ( p [i] . y1 < p [i] . y2){
                    int x = p [i] . x1 ;
                    int y = p [i] . y1 ;
                    for ( ; x <= p [i] . x2 ; x += dx , y += dy )
                        pst . insert ( { x , y } ) ;
                }
                else{
                    int x = p [i] . x1 ;
                    int y = p [i] . y2 ;
                    for ( ; x <= p [i] . x2 ; x += dx , y += dy )
                        pst . insert ( { x , y } ) ;
                }
            }
            else{
                if ( p [i] . y1 < p [i] . y2){
                    int x = p [i] . x2 ;
                    int y = p [i] . y1 ;
                    for ( ; x <= p [i] . x1 ; x += dx , y += dy )
                        pst . insert ( { x , y } ) ;
                }
                else{
                    int x = p [i] . x2 ;
                    int y = p [i] . y2 ;
                    for ( ; x <= p [i] . x1 ; x += dx , y += dy )
                        pst . insert ( { x , y } ) ;
                }
            }
        }
    }
    cout << pst . size () << "\n" ;
    /*auto it = pst . begin () ;
    for ( ; it != pst . end () ; ++ it)
        cout << it -> first << " " << it -> second << "\n" ;*/
	return 0;
}