#include <iostream>
#include <fstream>
//#include <cstring>
using namespace std;
int U[100];
ifstream f("cifra.in");
ofstream g("cifra.out");
int ucif(int n)
{
    int uc=n%10, r=n%4, p=1;
    if(r==0) r=4;
    while(r--)
        p*=uc;
    return p%10;
}
int main()
{
    int T,ncif,rest;
    char sir[101];
    for(int i=1;i<100;i++)
     U[i]=(U[i-1]+ucif(i))%10;
    f>>T;
    f.ignore();
    while(T--)
    {
        f.getline(sir,101);
       // ncif=strlen(sir);
       ncif=f.gcount()-1;
        rest=sir[ncif-1]-'0';
        if(ncif>=2)
            rest+=(sir[ncif-2]-'0')*10;
        g<<U[rest]<<'\n';
    }
    f.close();
    g.close();
    return 0;
}