S=input()
A=S.count('0')
B=S.count('1')
print(min(A,B)*2) S=input() S input() input A=S.count('0') A S.count('0') S.count S count '0' B=S.count('1') B S.count('1') S.count S count '1' print(min(A,B)*2) print min(A,B)*2 min(A,B) min A B 2 A=S.count('0') S.count('0') A B=S.count('1') S.count('1') B S=input() input() S
S=input()
A=S.count('0')
B=S.count('1')
print(min(A,B)*2)