import java.util.*;
import java.lang.*;
import java.io.*;
class Codechef
{
public static int recursiveSum(int num) {
if(num <= 1)
return num;
return num + recursiveSum(num - 1);
}
public static void main (String[] args) throws java.lang.Exception
{
System.out.println(recursiveSum(10));
}
}
// -----------------------------------------------------------