#include<stdio.h>
#include<stdlib.h>
#include<math.h>
main()
{
struct student
{
int id;
float h;
int w;
float bmi;
};
struct student a, b, c ,d;
a.h=1.5;
a.w=50;
a.bmi=(a.w/pow(a.h,2));
b.h=1.6;
b.w=55;
b.bmi=(b.w/pow(b.h,2));
c.h=1.7;
c.w=60;
c.bmi=(c.w/pow(c.h,2));
d.h=1.8;
d.w=65;
d.bmi=(d.w/pow(d.h,2));
printf("%.2f\n",(a.bmi+b.bmi+c.bmi+d.bmi)/4);
system("pause");
}