s = input()

s_0 = s.count("0")
s_2 = s.count("1")

print(min(s_0,s_2)*2) s = input() s input() input s_0 = s.count("0") s_0 s.count("0") s.count s count "0" s_2 = s.count("1") s_2 s.count("1") s.count s count "1" print(min(s_0,s_2)*2) print min(s_0,s_2)*2 min(s_0,s_2) min s_0 s_2 2 s_0 = s.count("0") s.count("0") s_0 s_2 = s.count("1") s.count("1") s_2 s = input() input() s
s = input()

s_0 = s.count("0")
s_2 = s.count("1")

print(min(s_0,s_2)*2)
