S = input()

ones = S.count('1')
zeros = S.count('0')
print(min(ones, zeros) * 2) S = input() S input() input ones = S.count('1') ones S.count('1') S.count S count '1' zeros = S.count('0') zeros S.count('0') S.count S count '0' print(min(ones, zeros) * 2) print min(ones, zeros) * 2 min(ones, zeros) min ones zeros 2 ones = S.count('1') S.count('1') ones zeros = S.count('0') S.count('0') zeros S = input() input() S
S = input()

ones = S.count('1')
zeros = S.count('0')
print(min(ones, zeros) * 2)