#File: Erin/intersection.py
"""Given two lists, computes the
union and intersection of the two lists. Improve solution
list1?  4 5 6
list2?  6 7 8 9
L1 = ['4', '5', '6'] L2 = ['6', '7', '8', '9']
intersection = ['6']
union        = ['4', '5', '6', '7', '8', '9']
"""
def intersection(L1, L2):
    R = []          #R result nothing inside
    for e in L1:    # conmpare all with all
        for k in L2:
            if ( e == k):
                R.append(e) # only if they are equal put in R
    return R

def union(L1, L2):
    L = L1 + L2       # put all toghether
    R = []
    [ R.append(x) for x in L if x not in R ] # remove duplicates
    return R

def main():
    L1 = input( "list1?  " ).split( " " ) # input
    L2 = input( "list2?  " ).split( " " )
    
    print ("L1 =", L1, "L2 =", L2)
    print ("intersection =", intersection( L1,L2 ))
    print ("union        =", union( L1, L2 ))
     
main()