#include<stdio.h>
int main()
{
int year;
scanf("%d\n",&year);
if(year<1)
{
printf("Invalid Input");
}
else if(1<year<=5);
{
printf("5%",year);
}
else if(6<year<=10)
{
printf("10%",year);
}
else
{
printf("15%",year);
}
return 0;
}