#include <stdio.h>
#include <math.h>

struct point {
    double x;
    double y;
    char name[4];
};

double distance (struct point a, struct point b) {
    double d1 = a.x - b.x;
    double d2 = a.y - b.y;
    return sqrt(d1*d1+d2*d2);
}

int main() {

    struct point d = {2.4, 6.2, "pt1"};
    struct point e = {5.6, 3.4, "pt2"};

    double a1 = distance(d, e);
    printf("%f\n", a1);





    return 0;


}