#include <fstream>
#include <sstream>
#include <string>
using namespace std;

int main()
{
    ifstream f("cifra.in");
    ofstream g("cifra.out");
    long long a[100];
    int i,j;
    a[0]=0;
    for (i=1; i<100; i++)
    {
        a[i]=i%10;
        for (j=1; j<i; j++) a[i]=(a[i]*i)%10;
        a[i]=(a[i]+a[i-1])%10;
    }
    string s;
    int n,t;
    f >> n;
    for (i=0; i<n; i++)
    {

        f >> s;
        s='0'+s;
        s=s.substr(s.size()-2,2);
        t=s[0]+s[1]-2*'0';
        g << a[t]%10 << endl;
    }
}