s = input()
one = s.count("1")
zero = s.count("0")

print(min(zero,one)*2) s = input() s input() input one = s.count("1") one s.count("1") s.count s count "1" zero = s.count("0") zero s.count("0") s.count s count "0" print(min(zero,one)*2) print min(zero,one)*2 min(zero,one) min zero one 2 s = input() input() s one = s.count("1") s.count("1") one zero = s.count("0") s.count("0") zero
s = input()
one = s.count("1")
zero = s.count("0")

print(min(zero,one)*2)