letters = {("x.","xx"):"A",("xx","xx"):"B",("x.x","xxx"):"C",("xx",".x"):"D",("xxx",".xx"):"E"}
    
fin = open("DATA4.txt","r")
fout = open("OUT4.txt","w")

def parse(top,bottom,buff=""):
    if top=="":
        return buff
    if len(top)==1:
        return -1
    if (top[0:2],bottom[0:2]) in letters:
        ret = parse(top[2:],bottom[2:],buff+letters[(top[0:2],bottom[0:2])])
        if ret != -1:
            return ret
    if (top[0:3],bottom[0:3]) in letters:
        ret = parse(top[3:],bottom[3:],buff+letters[(top[0:3],bottom[0:3])])
        if ret != -1:
            return ret
    return -1

for i in range(5):
    top = fin.readline().strip("\n ")
    bottom = fin.readline().strip("\n ")
    fout.write(parse(top,bottom)+"\n")
    
fin.close()
fout.close()