#include <iostream>
#include <GL/freeglut.h>
using namespace std;
void display1(void)
{
    glClearColor(1,0,1,0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glutSwapBuffers();
    glutPostRedisplay();
}
void display2(void)
{
    glClearColor(1,0,1,0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glutSwapBuffers();
    glutPostRedisplay();
}
void display3(void)
{
    glClearColor(1,0,1,0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glutSwapBuffers();
    glutPostRedisplay();
}
void display4(void)
{
    glClearColor(1,0,1,0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glutSwapBuffers();
    glutPostRedisplay();
}
int main(int argc, char **argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutInitWindowSize(200, 50);
    glutCreateWindow("1");
    glutSetOption(GLUT_ACTION_ON_WINDOW_CLOSE, GLUT_ACTION_CONTINUE_EXECUTION);
    glutDisplayFunc(display1);
    glutMainLoop();
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutInitWindowSize(1000, 1000);
    glutCreateWindow("2");
    glutSetOption(GLUT_ACTION_ON_WINDOW_CLOSE, GLUT_ACTION_CONTINUE_EXECUTION);
    glutDisplayFunc(display2);
    glutMainLoop();
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutInitWindowSize(200, 50);
    glutCreateWindow("3");
    glutSetOption(GLUT_ACTION_ON_WINDOW_CLOSE, GLUT_ACTION_CONTINUE_EXECUTION);
    glutDisplayFunc(display3);
    glutMainLoop();
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutInitWindowSize(1000, 1000);
    glutCreateWindow("4");
    glutSetOption(GLUT_ACTION_ON_WINDOW_CLOSE, GLUT_ACTION_CONTINUE_EXECUTION);
    glutDisplayFunc(display4);
    glutMainLoop();
}