#include <iostream>
#include <fstream>
#include <math.h>
#include <string.h>
#include <stdlib.h>
using namespace std;
ifstream f("cifra.in");
ofstream g("cifra.out");
int T,P[]={0,1,5,2,8,3,9,2,8,7},lg;
int I[]={0,1,7,0,6,1,7,4,8,7};
long S,cat;
char Numar[30005][1005],caracter,caracter1;

int main()
{
     f>>T;
     for(int i=1;i<=T;i++)
     {
         f.get(); f.get(Numar[i],1005);
         lg=strlen(Numar[i]); S=0;
         caracter=Numar[i][lg-2]; caracter1=Numar[i][lg-1];
         if(((atoi(&caracter)/10)%10)%2==0)
         { S+=2*((atoi(&caracter)/10)%10); S+=P[atoi(&caracter1)]; }
         else
         { S+=2*(((atoi(&caracter)/10)%10)-1)+7; S+=I[atoi(&caracter1)]; }
         g<<S%10<<'\n';
     }
    return 0;
}