Uri 1002 problem solution

Uri 1002 problem solution please don't copy code .If you don't understand the problem than you find logic here see this code.

Code is here:

#include <stdio.h>

int main() {

     double A,R;

     scanf("%lf",&R);

     A=3.14159*R*R;

     printf("A=%.4lf\n",A);

    return 0;
}