#include <stdio.h>

int main()
 {
	int units;
    float bill;

     scanf("%d", &units);

      if (units <= 200)
         bill = 0;


      else if (units <= 400)
           bill = (units - 200) * 5;


   
      else if (units <= 600)
           bill = 200 * 5 + (units - 400) * 7;



      else if (units <= 800)
           bill = 200 * 5 + 200 * 7 + (units - 600) * 9;



     else
         bill = 200 * 5 + 200 * 7 + 200 * 9 + (units - 800) * 11;




      printf("electricity bill = %.0f rs", bill);
     


	return 0;
}