S = input()

zero = S.count("0")
one = S.count("1")

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

zero = S.count("0")
one = S.count("1")

print(2*min(zero,one))