#include <stdio.h>
#include <stdbool.h>
//verifying point validity
int main(void)
{
    int x1, y1, x2, y2, x3, y3, x4, y4;

    printf("Enter point #1:\n");
    if (scanf("%d%d", &x1,&y1)==2)
    {
        goto two;
    }
    else
    {
        printf("Invalid Entry\n");
    }
two:
    printf("Enter point #2:\n");
    if (scanf("%d%d", &x2,&y2)==2)
    {
        goto three;
    }
    else
    {
        printf("Invalid Entry\n");
    }
three:
    printf("Enter point #3:\n");
    if (scanf("%d%d", &x3,&y3)==2)
    {
        goto four;
    }
    else
    {
        printf("Invalid Entry\n");
    }
four:
    printf("Enter point #4:\n");
    if (scanf("%d%d", &x4,&y4)==2)
    {
        goto next;
    }
    else
    {
    printf("Invalid Entry\n");
    }
next:



}

//function for verifying rectangle

static bool IsRectangle(int x1, int y1, int x2, int y2,
                        int x3, int y3, int x4, int y4)
{
    x2 -= x1; x3 -= x1; x4 -= x1; y2 -= y1; y3 -= y1; y4 -= y1;
    return
    (x2 + x3 == x4 && y2 + y3 == y4 && x2 * x3 == -y2 * y3) ||
    (x2 + x4 == x3 && y2 + y4 == y3 && x2 * x4 == -y2 * y4) ||
    (x3 + x4 == x2 && y3 + y4 == y2 && x3 * x4 == -y3 * y4);
}