#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;
	}
}
void 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+a[cifra1%20])%10;
		fprintf(g,"%d\n",cifra1);
	}
}