#include "bits/stdc++.h"
#include "graphics.h"
using namespace std;

int main() {
	int _driver = DETECT,gm;
	initgraph(&_driver,&gm,(char*)"");
	int x0,x1,y0,y1;
	cin >> x0 >> y0 >> x1 >> y1;
	int dx = x1 - x0;
	int dy = y1 - y0;
	int start_x = x0,start_y = y0;
	int p = 2 * dy - dx;
	for (int rep = x0; rep <= x1; ++rep) {
//		cout << start_x << ' ' << start_y << '\n';
		putpixel(start_x,start_y,WHITE);
		delay(300);
		start_y += (p >= 0);
		p += (p >= 0 ? (2 * dy - 2 * dx) : (2 * dy));
		++start_x;
	}
}