using
System;
using
System.Collections.Generic;
public
class
GFG {
static
List<List<
int
> > combs =
new
List<List<
int
> >();
static
void
combinationUtil(
int
[] arr,
int
[] data,
int
start,
int
end,
int
index,
int
r)
{
if
(index == r) {
List<
int
> comb =
new
List<
int
>();
for
(
int
j = 0; j < r; j++)
comb.Add(data[j]);
combs.Add(comb);
return
;
}
for
(
int
i = start;
i <= end && end - i + 1 >= r - index; i++) {
data[index] = arr[i];
combinationUtil(arr, data, i + 1, end,
index + 1, r);
}
}
static
int
count_seq(
int
[] arr,
int
n,
int
k)
{
int
ans = 0;
foreach
(List<
int
> seq
in
combs)
{
int
pro = 1;
foreach
(
int
ele
in
seq) pro *= ele;
if
((pro % 4) != 2)
ans += 1;
}
return
ans;
}
static
public
void
Main()
{
int
[] arr = { 2, 5, 6 };
int
n = arr.Length;
int
k = 2;
combinationUtil(arr,
new
int
[k], 0, n - 1, 0, k);
Console.WriteLine(count_seq(arr, n, k));
}
}