#include<stdio.h>
#include<string.h>
using namespace std;
FILE*in=fopen("cifra.in","r");
FILE*out=fopen("cifra.out","w");
int numerotare[2][10],t,i,j,q,k,z,y;
char v[100],caracter;
int main()
{
fscanf(in,"%d",&t);
for(i=0;i<t;i++)
{
    fscanf(in,"%c",&caracter);
    if(caracter>=48 && caracter<=57)
    {
        v[y]=caracter;
        y++;
    }
    z=strlen(v)-1;
    k=v[strlen(v)]-48;
    if(k==0)
        q=0;
        else
        if(k==1)
            q=1;
            else
            if(k==9)
                q=7;
                else
                if(k==3)
                    if(strlen(v)-1%2==0)
                        q=0;
                    else
                        q=2;
                    else
                    if(k==4)
                        if(strlen(v)-1%2==0)
                            q=8;
                        else
                            q=6;
                            else
                            if(k==2)
                                if(strlen(v)-1%2==0)
                                    q=5;
                                else
                                    q=7;
                                    else
                                    if(k==5)
                                        if(strlen(v)-1%2==0)
                                            q=1;
                                        else
                                            q=3;
                                            else
                                            if(k==6)
                                                if(strlen(v)-1%2==0)
                                                    q=9;
                                                else
                                                    q=7;
                                                    else
                                                    if(k==7)
                                                        if(strlen(v)-1%2==0)
                                                            q=4;
                                                        else
                                                            q=2;
                                                            else
                                                            if(k==8)
                                                                q=8;

fprintf(out,"%d\n",(7*z+q)%10);
}

fclose(in);
fclose(out);
return 0;
}