#include <stdio.h>
#include <math.h>
struct point
{
float x;
float y;
};
int main()
{
struct point p1,p2;
scanf("%f%f",&p1.x,&p1.y);
scanf("%f%f",&p2.x,&p2.y);
float m,n,a,b,c,d;
m=p1.x-p2.x;
n=p1.y-p2.y;
a=m*m;
b=n*n;
c=a+b;
d=sqrt(c);
printf("%.2f",d);
}
网友评论