#include <iostream>
using namespace std;

void main()
{
    int ar[10];
    int sum = 0;

    for (int i = 0; i<10; i++)
        ar[i] = i + 1;

    for (int i = 0; i<10; i++)
    if (i % 2 != 0)
        sum += ar[i];

    cout << sum;
}