s = input()
n0 = s.count('0')
n1 = s.count('1')
ans = min(n0,n1) * 2
print(ans) s = input() s input() input n0 = s.count('0') n0 s.count('0') s.count s count '0' n1 = s.count('1') n1 s.count('1') s.count s count '1' ans = min(n0,n1) * 2 ans min(n0,n1) * 2 min(n0,n1) min n0 n1 2 print(ans) print ans n0 = s.count('0') s.count('0') n0 s = input() input() s ans = min(n0,n1) * 2 min(n0,n1) * 2 ans n1 = s.count('1') s.count('1') n1
s = input()
n0 = s.count('0')
n1 = s.count('1')
ans = min(n0,n1) * 2
print(ans)