#include <stdio.h>

int get_sum_divisor( int n )
{
  int x, sum;

  sum = 0;
  for ( x = 1; x <= n; x++ )
  {
    sum += x;
  }

  return sum;
}

int main(void)
{
  int k;

  for ( k = 5; k <= 15; k += 5 )
  {
    printf("%3d の約数の合計 = %d\n", k, get_sum_divisor(k));
  }

  return 0;
}