#include<stdio.h>
#include<string.h>
FILE *in=fopen("cifra.in","r");
FILE *out=fopen("cifra.out","w");
int n,i,j,k,nr,s,x;
char sir[105];
int main()
{
	fscanf(in,"%d",&n);
	for(i=1;i<=n;i++)
	{
		fscanf(in,"%s",sir);
		x=strlen(sir);
		x=sir[x-1]-'0';
		nr=0;
		for(j=1;j<=x;j++)
		{
			s=1;
			for(k=1;k<=j;k++)
			{
				s=(s*j)%10;
			}
			nr=(nr+s)%10;
		}
		fprintf(out,"%d\n",nr);
	}
	return 0;
}