#include <iostream>
using namespace std;
int main(){
    int score = 0, t;
    int pre = 0;
    while(cin >> t && t){
        if(t == 1)  pre = 1, score += t;
        else{
            if(pre == 1)    pre = 2, score += 2;
            else    pre = pre + 2, score += pre;
        }
    }
    cout << score << endl;
    return 0;
}