using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;

class TEST{
	static void Main(){
		Sol mySol =new Sol();
		mySol.Solve();
	}
}

class Sol{
	public void Solve(){
		int W = 16;
		long carry = (long)Math.Pow(10,W);
		String pad = "";
		while((S.Length + pad.Length)%W != 0)pad += "0";
		S = pad + S;
		int N = S.Length;
		int NN = N/W;
		long[] dp = new long[NN];
		for(int i=0;i<NN;i++){
			dp[i] = long.Parse(S.Substring(i*W,W));
		}
//Console.WriteLine("{0} {1}",S,String.Join(" ",dp));		
		int t = 0;
		int cnt = 0;
		while(true){
			for(int i=t;i<NN-1;i++){
				if( (dp[i] & 1) == 1 )dp[i+1] += carry;
				dp[i] >>= 1;
			}
			if((dp[NN-1] & 1 ) == 1)cnt++;
			dp[NN-1] >>= 1;
			if(dp[t] == 0)t++;
			if(t==NN)break;
		}
		
		Console.WriteLine(cnt);
		
	}
	String S;
	public Sol(){
		S = rs();
	}

	static String rs(){return Console.ReadLine();}
	static int ri(){return int.Parse(Console.ReadLine());}
	static long rl(){return long.Parse(Console.ReadLine());}
	static double rd(){return double.Parse(Console.ReadLine());}
	static String[] rsa(char sep=' '){return Console.ReadLine().Split(sep);}
	static int[] ria(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>int.Parse(e));}
	static long[] rla(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>long.Parse(e));}
	static double[] rda(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>double.Parse(e));}
}