#include <iostream>

using namespace std;

int main ()
{
    int a, i, n, b, c, d;

    n = 2;
    c = 0;

    for ( i = 1; i = 11; i++)
        {
        cin >> a;
        b = 0;

        if (a > 3)
            {
            while (2 * n <= a)
                {
                if (a % n == 0)
                    b++;
                n++;
                }
            }
        else
            {
                switch (a)
                {
                    case 1:
                        {
                            b = 1;
                        }
                    case 2:
                        {
                            b = 2;
                        }
                    case 3:
                        {
                            b = 2;
                        }
                }
            }
        c = c + b;
        }
    d = c % 10;

    cout << d;

    return 0;
}