s=input()
s=[i for i in s]
ans=min(s.count('0'),s.count('1'))
print(2*ans) s=input() s input() input i for i in s for i in s i s for i in s i s=[i for i in s] s [i for i in s] ans=min(s.count('0'),s.count('1')) ans min(s.count('0'),s.count('1')) min s.count('0') s.count s count '0' s.count('1') s.count s count '1' print(2*ans) print 2*ans 2 ans ans=min(s.count('0'),s.count('1')) min(s.count('0'),s.count('1')) ans s=[i for i in s] [i for i in s] s s=input() input() s
s=input()
s=[i for i in s]
ans=min(s.count('0'),s.count('1'))
print(2*ans)