import collections
s = input()
c0 = s.count('0')
c1 = len(s) - c0
print(min(c0,c1)*2) import collections collections s = input() s input() input c0 = s.count('0') c0 s.count('0') s.count s count '0' c1 = len(s) - c0 c1 len(s) - c0 len(s) len s c0 print(min(c0,c1)*2) print min(c0,c1)*2 min(c0,c1) min c0 c1 2 s = input() input() s c0 = s.count('0') s.count('0') c0 c1 = len(s) - c0 len(s) - c0 c1
import collections
s = input()
c0 = s.count('0')
c1 = len(s) - c0
print(min(c0,c1)*2)