#include<stdio.h>
#include<string.h>
using namespace std;
int imp[]={0,1,4,7,6,5,6,3,6,9,0};
int par[]={0,1,6,3,6,5,6,7,4,9,0};
int S,x,n,j,L,tu,tl;
char sir[120];
int main ()
{
	freopen ("cifra.in","r",stdin);
	freopen ("cifra.out","w",stdout);
	scanf("%d",&n);
	for(int i=1;i<=n;++i)
	{
		S=0;
		scanf("%sir",sir);
		L=strlen(sir);
		tl=int(sir[L-1])-48;
		tu=int(sir[L-2])-48;
		if(tu<0)
			for(j=1;j<=tl;++j)
				S=S+imp[j];
		else
		if(tu%2==0)
		{
			for(j=1;j<=tl;++j)
				S=S+imp[j];
		}
		else
		{
			for(j=1;j<=tl;++j)
				S=S+par[j];
		}
		printf("%d\n",S%10);
	}
	return 0;
}