S = input()
X = S.count('0')
Y = S.count('1')
print(2*min(X,Y)) S = input() S input() input X = S.count('0') X S.count('0') S.count S count '0' Y = S.count('1') Y S.count('1') S.count S count '1' print(2*min(X,Y)) print 2*min(X,Y) 2 min(X,Y) min X Y Y = S.count('1') S.count('1') Y X = S.count('0') S.count('0') X S = input() input() S
S = input()
X = S.count('0')
Y = S.count('1')
print(2*min(X,Y))