a=int(input())
b=[]
c=1
for i in range(1,33):
    b.append(c)
    c=c*2
for i in range(0,32):
    if(abs(b[i]-a)>=abs(b[i+1]-a) and abs(b[i+1]-a)<=abs(b[i+2]-a)):
        print(b[i+1])
        break
/**************************************************************
	Problem: 1075
	User: admin
	Language: Python
	Result: Accepted
	Time:85 ms
	Memory:34480 kb
****************************************************************/