C :

#include <stdio.h>
int main(){
	int n,i = 2;
	scanf("%d",&n);
	while(i < n){
		i *= 2;
	}
	if(i - n < n - i / 2)
		printf("%d",i);
	else
		printf("%d",i/2);
	
}

C++ :

#include<iostream>
using namespace std;
int main(){ 
   int n,i;
   cin>>n;
   i = 2;
   while(i < n){ 
     i = i * 2;
   }
   if(i - n < n - i / 2){ 
      cout<<i<<endl;
   }else{ 
      cout<<i / 2 <<endl;
   }
    
   return 0;
}

Pascal :

var  i:integer;
     n,t:int64;
     a:array[0..31] of int64;
begin
  readln(n);
  t:=1; a[0]:=1;
  for i:=1 to 31 do
    begin
     t:=t*2;
     a[i]:=t;
    end;
  i:=0;
  while n>a[i] do inc(i);
  if (a[i]-n) >= (n-a[i-1]) then write(a[i-1]) else write(a[i]);
end.

Java :

import java.util.Scanner;
public class Main{
	public static void main(String[] args) {
		int n=new Scanner(System.in).nextInt();
		int l1=0;
		int l2=0;
		for(int k=1;k<=n;k++){
			if(Math.pow(2,k)<=n&&Math.pow(2,k+1)>=n){
				l1=n-(int) Math.pow(2,k);
				l2=(int) Math.pow(2,k+1)-n;
				if(l1<=l2){
					System.out.println((int) Math.pow(2,k));
				}else{
					System.out.println((int) Math.pow(2,k+1));
				}
			}	
		}
	}
}

Python :

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