import collections
S = input()
col_S = collections.Counter(S) 
print(min(col_S['0'],col_S['1'])*2) import collections collections S = input() S input() input col_S = collections.Counter(S) col_S collections.Counter(S) collections.Counter collections Counter S print(min(col_S['0'],col_S['1'])*2) print min(col_S['0'],col_S['1'])*2 min(col_S['0'],col_S['1']) min col_S['0'] col_S '0' col_S['1'] col_S '1' 2 col_S = collections.Counter(S) collections.Counter(S) col_S S = input() input() S
import collections
S = input()
col_S = collections.Counter(S) 
print(min(col_S['0'],col_S['1'])*2)
