#include <stdio.h>
#include <stdlib.h>
#include <math.h>
struct point
{
       int xpos;
       int ypos;
       };

int main(void)
{
    struct point pos1,pos2;
    double distance;
   
    fputs("point1 pos: ", stdout);
    scanf("%d %d", &pos1.xpos, &pos1.ypos);
   
    fputs("point2 pos: ", stdout);
    scanf("%d %d", &pos2.xpos, &pos2.ypos);
   
    distance=sqrt((double)((pos1.xpos-pos2.xpos)*(pos1.xpos-pos2.xpos)+(pos1.ypos-pos2.ypos)*(pos1.ypos-pos2.ypos)));
   
    printf("두 점의 거리는 %g 입니다. \n", distance);
    system("pause");
    return 0;
}