#include<stdio.h>
#include<stdlib.h>
#include<math.h>
main()
{
struct student
{
int id;
float h;
int w;
};
struct student a, b, c;
a.h=1.5;
a.w=50;
b.h=1.6;
b.w=55;
c.h=1.7;
c.w=60;
printf("%5.2f\n",((a.w/pow(a.h,2))+(b.w/pow(b.h,2))+(c.w/pow(c.h,2)))/3);
system("pause");
}