#include<iostream>
#include<stdio.h>
#include<string.h>
FILE *f,*g;
unsigned short a[21],cifra1;
void cifra()
{
    unsigned short p,s=0,i,j;
    for(i=1;i<=21;i++)
    {
        p=1;
        for(j=1;j<=i;j++)
            p=(p*i)%10;
        s=(s+p)%10;
        a[i]=s;
    }
}
int main()
{
    f=fopen("cifra.in","r");
    g=fopen("cifra.out","w");
    unsigned long n;
    fscanf(f,"%ld\n",&n);
    char c[101];
    a[0]=0;
    cifra();
    for(int i=1;i<=n;i++)
    {
        fscanf(f,"%s\n",&c);
        if(strlen(c)==1)
            cifra1=c[0]-'0';
        else
            cifra1=(c[strlen(c)-1]-'0'+10*(c[strlen(c)-2]-'0'));
        cifra1=((cifra1/20*4)%10+a[cifra1%20])%10;
        fprintf(g,"%d\n",cifra1);
    }
    return 0;
}