# while Loops functions
def display_list(L):
    i = 0
    while i < len(L):
        print(L[i])
        i += 1
        
def display_list_even(L):
    i = 0
    while i < len(L):
        if i % 2 == 0:
            print(L[i])
        i += 1
        
def display_list_reverse(L):
    i = len(L)-1
    while i >= 0:
        print(L[i])
        i -= 1
        
def sum_elements(L):
    i = 0; sum = 0
    while i < len(L) and sum <= 100:
        sum += L[i]
        i += 1
    return sum

def duplicates(L):
    i = 0
    while i+1 < len(L):
        if L[i] == L[i+1]:
            return True
        i += 1
    return False

if __name__ == '__main__':
    list1 = [0,2,4,6,8,1,3,5,7,9]
    list2 = [0,2,4,6,8,1,3,5,7,7,9]
    print(duplicates(list1))
    print(duplicates(list2))
    print(sum_elements(list1))
    display_list_reverse(list1)
    display_list_even(list1)
    display_list(list1)