#include <iostream>
#include <queue>
#include <cmath>
#include <vector>
using namespace std;

int rec(int x) {
    if(x > 5) {
        return 0;
    }
    return x + rec(x + 1);
}
int main()
{
    
    cout << rec(1) << endl;
  
    return 0;
}
// rec(1) = 1 + rec(2) = 1 + 14 = 15
// rec(2) = 2 + rec(3) = 2 + 12 = 14
// rec(3) = 3 + rec(4) = 3 + 9 = 12
// rec(4) = 4 + rec(5) = 4 + 5 = 9
// rec(5) = 5 + rec(6) = 5 + 0 = 5
// rec(6) = 0