#include <fstream>
#include<string.h>
#include<math.h>
using namespace std;
int main()
{
    unsigned int a,n=0,uc,c,t,i=0,ss=0;
    char s[100];
    ifstream f("cifra.in");
    ofstream g("cifra.out");
    f>>t;
    while(i<t)
    {
        f>>s;
        a=strlen(s);
        ss=0;
        n=0;
        c=s[a-1]-'0';
        while(n<=c)
        {
            ss=ss+pow(n,n);
            n++;
        }
        ss--;
        uc=ss%10;
        i++;
        g<<uc<<"\n";
    }
    f.close();
    g.close();

    return 0;
}