import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*;

class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner in = new Scanner(System.in);
		double currentNumber = in.nextDouble();
		double previousNumber = 0;
		double position = 0;
		for(; currentNumber >= 0; position++){
			previousNumber = currentNumber;
			currentNumber = in.nextDouble();
		}
		double result = position + previousNumber;
		System.out.println(result);	
	}
}