#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <conio.h>

int a,b,T,i,j,l,S1,S2,nr;
char x[101];
int v[11]={0,1,4,7,6,5,6,3,6,9};

void calcul ()
{
    FILE *f=fopen("cifra.in", "r");
    FILE *g=fopen("cifra.out", "w");
    fscanf(f,"%d", &T);
    for(i=1;i<=T;i++)
    {
        for(j=0;j<=100;j++)
            x[j]=0;
        fgets(x,100,f);
        l=strlen(x);

    if(l>1)
        a=x[l-2]-'0';
    else
        a=0;
    b=x[l-1]-'0';
    S1=0;
    for(j=0;j<=b;j++)
        S1+=v[j];
        S2=(7*a)%10;
        nr=(S1+S2)%10;
    fprintf(g,"\n%d", nr);
    }
    fclose(f);
    fclose(g);
}
int main ()
{
    calcul();
    getch();
    return 0;
}