/* package whatever; // don't place package name! */

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

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		int[] a = new int[]{0, 5, 5, 10, 100, 10, 5};
		int n = a.length-1;

		long[] dp = new long[n + 1];


		dp[0] = 0;  
		dp[1] = a[1];

		for(int i = 2; i <= n; i++){
			dp[i] = Math.max(Math.max(a[i], dp[i-2] + a[i]), dp[i-1]); 
		}

		System.out.println(dp[n]);
	}
}