# coding: utf-8
# Your code here!

D=int(input())

MAX_BOUND=64

def calc_distance(init_power):
    rev=0
    while init_power:
        rev+=init_power
        init_power//=2
        
    return rev

ans=D
for k in range(MAX_BOUND):
    high=2**(k+1)-1
    low=2**k
    
    #error判定
    high_distance=calc_distance(high)
    low_distance=calc_distance(low)
    
    if low_distance<=D<=high_distance:
        pass
    else:
        continue
    
    while high-low>1:
        middle=(high+low)//2
        
        distance=calc_distance(middle)
        
        if distance>=D:
            high=middle
        else:
            low=middle
            
    ans=min(ans,middle)

print(ans)