
S = input()
num_0 = S.count("0")
num_1 = S.count("1")
print(2 * min(num_0, num_1)) S = input() S input() input num_0 = S.count("0") num_0 S.count("0") S.count S count "0" num_1 = S.count("1") num_1 S.count("1") S.count S count "1" print(2 * min(num_0, num_1)) print 2 * min(num_0, num_1) 2 min(num_0, num_1) min num_0 num_1 num_1 = S.count("1") S.count("1") num_1 num_0 = S.count("0") S.count("0") num_0 S = input() input() S

S = input()
num_0 = S.count("0")
num_1 = S.count("1")
print(2 * min(num_0, num_1))
