# [2, 3, 7, 4, 3, 2, 6, 1, 8] -> [2, 4, 2, 6, 8].


print('Løsning 1')

X = [2, 3, 7, 4, 3, 2, 6, 1, 8]
Y = X.copy()
for x in Y:
    #print(X)
    #print(x)
    if x % 2:
        #print('remove', x)
        X.remove(x)
print(X)

print('Løsning 2')

X = [2, 3, 7, 4, 3, 2, 6, 1, 8]
for i in range(len(X))[::-1]:
    #print('i =', i, 'X =', X)
    if X[i] % 2 == 1:
        del X[i]
print(X)

print('Løsning 3')

X = [2, 3, 7, 4, 3, 2, 6, 1, 8]
Y = []
for x in X:
#    print('i =', i, 'X[i] =', x, 'Y =', Y)
    if x % 2 == 0:
        Y.append(x)
print(Y)

print('Løsning 4')

X = [2, 3, 7, 4, 3, 2, 6, 1, 8]
Y = [x for x in X if x % 2 == 0]
print(Y)

print('Løsning 5')

X = [2, 3, 7, 4, 3, 2, 6, 1, 8]
i = 0
while i < len(X):
#    print(i, X)
    if X[i] % 2 == 1:
        del X[i]
    else:
        i = i + 1
print(X)