#思路:转2进制之后双层循环遍历,判断

a=int(input())
a=bin(a)[2:]
max=0
for i in range(len(a)):
    for j in range(i+1,len(a)+1):
        if len(a[i:j])==a[i:j].count("1") and j-i>max:
            max=j-i
print(max)