S = input()

C0 = S.count("0")
C1 = S.count("1")

ans = 2 * min(C0, C1)
print(ans) S = input() S input() input C0 = S.count("0") C0 S.count("0") S.count S count "0" C1 = S.count("1") C1 S.count("1") S.count S count "1" ans = 2 * min(C0, C1) ans 2 * min(C0, C1) 2 min(C0, C1) min C0 C1 print(ans) print ans C0 = S.count("0") S.count("0") C0 S = input() input() S C1 = S.count("1") S.count("1") C1 ans = 2 * min(C0, C1) 2 * min(C0, C1) ans
S = input()

C0 = S.count("0")
C1 = S.count("1")

ans = 2 * min(C0, C1)
print(ans)