#include <fstream>
#include <cstring>
using namespace std;
int main()
{
    ifstream fin ("cifra.in");
    ofstream fout ("cifra.out");
    int t,a[10]={1,4,7,6,5,6,3,4,1,0};
    fin>>t;
    int ult=0,dat;
    char ch[100];
    fin.get();
    for(int i=0;i<t;i++)
    {
        fin.getline(ch,100);
        if(strlen(ch)>1) ult=(7*ch[strlen(ch)-2]-'0')%10;
        dat=ch[strlen(ch)-1]-'0';
        for(int i=0;i<dat;i++) ult+=a[i];
        fout<<ult%10<<"\n";
        ult=0;
        strcpy(ch,"");
    }
}