#include<stdio.h>
#include<iostream>
#include<string.h>
using namespace std;
int main()
{
	FILE *in,*out;
	in=fopen("cifra.in","rt");
	out=fopen("cifra.out","wt");
	int cif[10][4];
	int i,j,k,c=0,r=0,p;
	char N[110];
	for(i=0;i<10;i++)
	{
		cif[i][0]=i;
		for(j=1;j<4;j++)
		{
			cif[i][j]=(cif[i][j-1]*i)%10;
		}
	}
	fscanf(in,"%d",&j);
	while(j)
	{
		r=0;
		c=0;
		fscanf(in,"%s",N);
		p=strlen(N);
		if(p>=2)
		{
			k=(N[p-2]-'0')*10+(N[p-1]-'0');
		}
		else
		{
			k=N[p-1]-'0';
		}
		while(k>20)
		{
			k=k-20;
			c=c+4;
		}
		c=c%10;
		for(i=1;i<=k;i++)
		{
			if(i%10==0)
			{
				r+=10;
			}
			if(i%4==0)
			{
				c=c+cif[i-r][3];
			}
			else
			{
				c=c+cif[i-r][i%4-1];
			}
		}
		fprintf(out,"%d\n",c%10);
		j--;
	}
	return 0;
}