Bitwise: Number of 1 Bits

import java.util.*;
import java.lang.*;

class Main {

	static void couuntBits(int n){
		int count = 0; // variable to count set(1) bits

		for(int i=0; i<n; i++){
			if(checkBit(n, i)){ // check point for bit is set(1) or unset(0)
				count++; // increment count if bit is set(1)
			}	
		}
		System.out.println("count:"+count); // print the count of number of set bits.
	}

	static boolean checkBit(int n, int i){ // function to check each check bit is set(1) or unset(0)
		if(((n>>i)&1) == 1){ //right shift and 1 == 1
			//System.out.println("true: "+((n>>i)&1));	
			return true;
		}
		else{
			//System.out.println("false: "+((n>>i)&1));	
			return false;
		}
	}

	public static void main(String args[]) {
		// Your code goes here
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();

		
		couuntBits(n);
	}
}