S = input()
cnt_0 = S.count("0")
cnt_1 = len(S) - cnt_0
print(min(cnt_0, cnt_1) * 2) S = input() S input() input cnt_0 = S.count("0") cnt_0 S.count("0") S.count S count "0" cnt_1 = len(S) - cnt_0 cnt_1 len(S) - cnt_0 len(S) len S cnt_0 print(min(cnt_0, cnt_1) * 2) print min(cnt_0, cnt_1) * 2 min(cnt_0, cnt_1) min cnt_0 cnt_1 2 cnt_0 = S.count("0") S.count("0") cnt_0 cnt_1 = len(S) - cnt_0 len(S) - cnt_0 cnt_1 S = input() input() S
S = input()
cnt_0 = S.count("0")
cnt_1 = len(S) - cnt_0
print(min(cnt_0, cnt_1) * 2)
