#include <fstream>

using namespace std;



char s[102];
int n,div,cif,mod,sum[21],t,nr;
const int v[20]={0,1,4,7,6,5,6,3,6,9,0,1,6,5,6,7,4,9};

int main()
{
    ifstream f("cifra.in");
    ofstream g("cifra.out");
    int i,j=0;
    f>>t>>ws;
    sum[0]=0;
    for (i=1;i<=19;i++)
        sum[i]=(sum[i-1]+v[i])%10;
    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[j-1]-'0';
        div=(nr%100)/20;
        mod=(nr%100)%20;
        cif=(div*4+sum[mod])%10;;
        g<<cif<<"\n";
    }
    return 0;
}