import sys import math p = sys.stdin.readline().strip().split() q = sys.stdin.readline().strip().split() p_set = set(p+q) p_proba = {} q_proba = {} for m in p:     if(m in p_proba.keys()):         p_proba[m] = p_proba[m] + 1     else:         p_proba[m] = 1 for m in q:     if(m in q_proba.keys()):         q_proba[m] = q_proba[m] + 1     else:         q_proba[m] = 1 KL = 0.0 for m in p_set:     p_tmp = float(p_proba[m])/float(len(p))     q_tmp = float(q_proba[m])/float(len(q))     pdq = p_tmp/q_tmp     KL = KL + p_tmp * math.log(pdq,2) print(round(KL,2))