Butun sonlar K va N berilgan (K ≤ N). K dan N gacha (ikkalasi ham kiradi) barcha butun sonlarning yig'indisini toping.
func sumRange(K int, N int) int {
// ...
}
Input: K=1, N=10
Output: 55
Input: K=5, N=10
Output: 45
Input: K=3, N=7
Output: 25