백준 10773

백준 10773

#include<iostream>
#include<vector>

int main()
{
    int countNum;
    int result=0;
    std::vector<int> v;

    std::cin >> countNum;

    for (int i = 0; i < countNum; i++)
    {
        int num;
        std::cin >> num;
        if (num == 0)
        {
            v.pop_back();
            continue;
        }
        v.push_back(num);
    }
  
    for (auto i : v)
        result += i;
    std::cout << result;
}