#include <cstdio>
long long n, x, x1, x2, sum;
int main()
{
    scanf("%lld", &n);
    for (int i = 0; i < n; i++)
    {
        scanf("%lld", &x);
        if (!(x))
        {
            x1++;
        }
        else if (x == 1)
        {
            x2 = 1;
        }
        else
        {
            x2 = (x2 == 1) ? 1 : 2;
        }
        sum += x;
    }
    if (n == 1)
    {
        printf("%lld\n", sum);
    }
    else if (x2 == 1 && x1)
    {
        sum += x1 << 1;
        printf("%lld\n", sum);
    }
    else if (!(x1))
    {
        printf("%lld\n", sum);
    }
    else
    {
        sum += (x1 << 1) - 1;
        printf("%lld\n", sum);
    }
    return 0;
}

Subtask#3 & Subtask#4 WA