N = str(input())
one = N.count('1')
zero = N.count('0')

print(min(one,zero)*2) N = str(input()) N str(input()) str input() input one = N.count('1') one N.count('1') N.count N count '1' zero = N.count('0') zero N.count('0') N.count N count '0' print(min(one,zero)*2) print min(one,zero)*2 min(one,zero) min one zero 2 zero = N.count('0') N.count('0') zero one = N.count('1') N.count('1') one N = str(input()) str(input()) N
N = str(input())
one = N.count('1')
zero = N.count('0')

print(min(one,zero)*2)