#include <iostream>
#include <bits/stdc++.h>
using namespace std;
int ans=0;
int main()
{
    int  s;
    int t=0;
    int flag=0;
    int base=1;
    while(cin>>s&&s)
    {
        if(s==1)
        {
            base=1;
            ans+=base;
        }
        else
        {
            if(base==1)base++;
            else
            base+=2;
            ans+=base;
        }

    }
    cout<<ans<<endl;
    return 0;
}