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