s = input()
red = s.count('0')
blue = s.count('1')

print(min(red,blue)*2) s = input() s input() input red = s.count('0') red s.count('0') s.count s count '0' blue = s.count('1') blue s.count('1') s.count s count '1' print(min(red,blue)*2) print min(red,blue)*2 min(red,blue) min red blue 2 red = s.count('0') s.count('0') red blue = s.count('1') s.count('1') blue s = input() input() s
s = input()
red = s.count('0')
blue = s.count('1')

print(min(red,blue)*2)