# List/Dictionary Tiz/Quest Answers

# -------------------------------------------------
# 1.

def Properties(filename):
    try:
        f=open(filename,'rU')
        lines=f.read().split('\n')
        f.close()
    except:
        print 'Cannot open '+filename
        return {}
    answer={}
    for line in lines:
        words=line.split('=')
        if len(words)==2:
            answer[words[0]]=words[1]
    return answer

# --------------------------------------------------
# 2.

def PropSum(list_of_filenames):
    while True:
        look_for=raw_input('Which property to sum (or nothing to quit): ')
        look_for=look_for.strip()
        if look_for=='':
            return
        prop_sum=0
        for fname in list_of_filenames:
            dct=Properties(fname)
            if look_for in dct:
                if dct[look_for].isdigit():
                    prop_sum+=int(dct[look_for])
        print 'Total %s = %d\n' % (look_for,prop_sum)
        
# -------------------------------------------------
# 3.

def Interleave(A,B):
    answer=[]
    for i in range(max(len(A),len(B))):
        if i<len(A):
            answer.append(A[i])
        if i<len(B):
            answer.append(B[i])
    return answer

# -----------------------------------------------------
# Extra credit:

def mode(L):
    the_mode=L[0]
    mode_dups=L.count(L[0])
    for anumber in L[1:]:
        if L.count(anumber)>mode_dups:
            the_mode=anumber
            mode_dups=L.count(anumber)
    return the_mode