You are given an array $a$ consisting of $n$ positive integers. Find a non-empty subset of its elements such that their sum is even (i.e. divisible by $2$) or determine that there is no such subset.

Both the given array and required subset may contain equal values.


-----Input-----

The first line contains a single integer $t$ ($1 \leq t \leq 100$), number of test cases to solve. Descriptions of $t$ test cases follow.

A description of each test case consists of two lines. The first line contains a single integer $n$ ($1 \leq n \leq 100$), length of array $a$.

The second line contains $n$ integers $a_1, a_2, \ldots, a_n$ ($1 \leq a_i \leq 100$), elements of $a$. The given array $a$ can contain equal values (duplicates).


-----Output-----

For each test case output $-1$ if there is no such subset of elements. Otherwise output positive integer $k$, number of elements in the required subset. Then output $k$ distinct integers ($1 \leq p_i \leq n$), indexes of the chosen elements. If there are multiple solutions output any of them.


-----Example-----
Input
3
3
1 4 3
1
15
2
3 5

Output
1
2
-1
2
1 2



-----Note-----

There are three test cases in the example.

In the first test case, you can choose the subset consisting of only the second element. Its sum is $4$ and it is even.

In the second test case, there is only one non-empty subset of elements consisting of the first element, however sum in it is odd, so there is no solution.

In the third test case, the subset consisting of all array's elements has even sum.

Difficulty: interview

Starter code:

Solutions:
#list(map(int,input().split()))
t=int(input())
for i in range(t):
    n=int(input())
    it=list(map(int,input().split()))
    if n==1 and it[0]%2==1:
        print(-1)
    else:
        ind=-1
        ind2=-1
        ind3=-1
        for j in range(n):
            if it[j]%2==0:
                ind=j
            elif ind2==-1:
                ind2=j
            else:
                ind3=j
            
        if ind==-1:
            print(2)
            print(ind2+1,ind3+1)
        else:
            print(1)
            print(ind+1)
        


import sys
import math
import itertools
import functools
import collections
import operator
import fileinput
import copy


ORDA = 97
def ii(): return int(input())
def mi(): return list(map(int, input().split()))
def li(): return list(map(int, input().split()))
def lcm(a, b): return abs(a * b) // math.gcd(a, b)
def revn(n): return str(n)[::-1]
def dd(): return collections.defaultdict(int)
def ddl(): return collections.defaultdict(list)
def sieve(n):
    if n < 2: return list()
    prime = [True for _ in range(n + 1)]
    p = 3
    while p * p <= n:
        if prime[p]:
            for i in range(p * 2, n + 1, p):
                prime[i] = False
        p += 2
    r = [2]
    for p in range(3, n + 1, 2):
        if prime[p]:
            r.append(p)
    return r
def divs(n, start=2):
    r = []
    for i in range(start, int(math.sqrt(n) + 1)):
        if (n % i == 0):
            if (n / i == i):
                r.append(i)
            else:
                r.extend([i, n // i])
    return r
def divn(n, primes):
    divs_number = 1
    for i in primes:
        if n == 1:
            return divs_number
        t = 1
        while n % i == 0:
            t += 1
            n //= i
        divs_number *= t
def prime(n):
    if n == 2: return True
    if n % 2 == 0 or n <= 1: return False
    sqr = int(math.sqrt(n)) + 1
    for d in range(3, sqr, 2):
        if n % d == 0: return False
    return True
def convn(number, base):
    newnumber = 0
    while number > 0:
        newnumber += number % base
        number //= base
    return newnumber
def cdiv(n, k): return n // k + (n % k != 0)


for _ in range(ii()):
    n = ii()
    a = li()
    if n == 1 and a[0] & 1:
        print(-1)
    else:
        for i in range(n):
            if a[i] % 2 == 0:
                print(1)
                print(i + 1)
                break
        else:
            print(2)
            print(1, 2)


from bisect import bisect_left as bl
from bisect import bisect_right as br
import heapq
import math
from collections import *
from functools import reduce,cmp_to_key
import sys
input = sys.stdin.readline
 
M = mod = 10**9 + 7
def factors(n):return sorted(set(reduce(list.__add__, ([i, n//i] for i in range(1, int(n**0.5) + 1) if n % i == 0))))
def inv_mod(n):return pow(n, mod - 2, mod)
 
def li():return [int(i) for i in input().rstrip('\n').split()]
def st():return input().rstrip('\n')
def val():return int(input().rstrip('\n'))
def li2():return [i for i in input().rstrip('\n').split(' ')]
def li3():return [int(i) for i in input().rstrip('\n')]

for _ in range(val()):
    n = val()
    a = li()
    if len(a) == 1 and a[0]&1:
        print(-1)
        continue

    if not a[0]&1:
        print(1)
        print(1)
    elif not a[1]&1:
        print(1)
        print(2)
    else:
        print(2)
        print('1 2')    

t = int(input().strip())
for _ in range(t):
    #a,b = map(int,input().strip().split())
    n = int(input().strip())
    nums = [int(i) for i in input().strip().split()]
    if n == 1 and nums[0] % 2 != 0:
        print(-1)
    else:
        has = False
        for i in range(n):
            if nums[i] % 2 == 0:
                ans = i
                has = True
                break
        if has:
            print(1)
            print(ans + 1)
        else:
            print(2)
            print(1,2)


import math, collections, sys
input = sys.stdin.readline
def solve():
    n = int(input())
    a = list(map(int, input().split()))
    if len(a) == 1:
        if a[0]%2:
            print(-1)
        else:
            print(1)
            print(1)
    else:
        flag = -1
        for i in range(n):
            if a[i]%2 == 0:
                flag = i+1
        if flag != -1:
            print(1)
            print(flag)
        else:
            print(2)
            print(1, 2)
for _ in range(int(input())):
    solve()

T = int(input())
for cas in range(T):
  n = int(input())
  a = [int(e) for e in input().split()]
  ok = False
  b = []
  for i, j in enumerate(a):
    if j % 2 == 0:
      print(1)
      print(i + 1)
      ok = True
      break
    else:
      b.append(i + 1)
    if len(b) >= 2:
      print(2)
      print(b[0], b[1])
      ok = True
      break
  if not ok:
    print(-1)


t = int(input())
for _ in range(t):
    n = int(input())
    a = [int(i) for i in input().split()]
    for i, e in enumerate(a):
        if e%2==0:
            print(1)
            print(i+1)
            break
    else:
        if len(a) >= 2:
            print(2)
            print(1,2)
            continue
        else:
            print(-1)
            continue

t = int(input())
for i in range(t):
    n = int(input())
    a = list(map(int, input().split()))
    if len(a) < 2 and a[0] % 2 == 1:
        print(-1)
    else:
        if a[0] % 2 == 0:
            print(1)
            print(1)
        elif a[1] % 2 == 0:
            print(1)
            print(2)
        else:
            print(2)
            print(1, 2)


import math
t=int(input())
for tt in range(t):
	n=int(input())
	arr=list(map(int,input().split()))
	flag=False
	odd=[]
	for i in range(len(arr)):
		if arr[i]%2==0:
			print(1)
			print(i+1)
			flag=True
			break
		else:
			odd.append(i+1)
			if  len(odd)%2==0:
				break
	if not flag:
		if len(odd)%2==1:
			print(-1)
			continue
		print(len(odd))
		for i in odd:
			print(i,end=" ")
		print()


from bisect import bisect_left as bl, bisect_right as br, insort
import sys
import heapq
from math import *
from collections import defaultdict as dd, deque
def data(): return sys.stdin.readline().strip()
def mdata(): return map(int, data().split())
#sys.setrecursionlimit(100000)

for i in range(int(input())):
    n=int(input())
    a=list(mdata())
    e=0
    o=0
    ind2=[]
    ind1=[]
    for i in range(n):
        if a[i]%2==0:
            e=1
            ind1=i+1
            break
        else:
            o+=1
            ind2.append(i+1)
    if e==1:
        print(1)
        print(ind1)
    elif o>=2:
        print(2)
        print(*ind2[:2])
    else:
        print(-1)

'''
    Auther: ghoshashis545 Ashis Ghosh
    college: jalpaiguri Govt Enggineering College
    Date:07/03/2020
'''
from math import ceil,sqrt,gcd,log,floor
from collections import deque
def ii(): return int(input())
def si(): return input()
def mi(): return map(int,input().strip().split(" "))
def li(): return list(mi())



for _ in range(ii()):
    n=ii()
    a=li()
    f=0
    for i in range(n):
        if(a[i]%2==0):
            print('1')
            print(i+1)
            f=1
            break
    if(f==0):
        if(n==1):
            print('-1')
        else:
            print('2')
            print(1,2)