#include <fstream>

using namespace std;

char s[102];

const int v[20]={0,1,4,7,6,5,6,3,6,9,0,1,6,5,6,7,4,9};
int sum[20];

int main()
{
    ifstream f("cifra.in");
    ofstream g("cifra.out");
    int i,t,j,nr,div,cif,mod;

    sum[0]=0;

    for(i=1;i<=19;i++)
        sum[i]=(sum[i-1]+v[i])%10;

    f>>t>>ws;
    for(i=1;i<=t;i++)
    {
        j=0;
        f.getline(s,102);
        while(s[j]) j++;
        if(j!=1)
        {
            nr=(s[j-2]-'0')*10+s[j-1]-'0';
        }
        else
        nr=s[0]-'0';
        div=(nr%100)/20;
        mod=(nr%100)%20;
        cif=(div*4+sum[mod])%10;
        g<<cif<<"\n";
    }

}