#include <fstream>
using namespace std;
ifstream f("cifra.in");
ofstream g("cifra.out");
long long n,t,z,d,i,j;
int main()
{
    f>>t;
    d=1;
    while(t>0) {f>>n;t=t-1;
    for(i=1;i<=n;i++)
        for(j=1;j<=i;j++) {d=d*i;}
    z=z+d;g<<z%10;}
    g.close();
    return 0;
}