#include <fstream>
using namespace std;
ifstream f("cifra.in");
ofstream g("cifra.out");
int n,v[5][10]={{0,0,0,0,0,0,0,0,0,0},
				{0,1,2,3,4,5,6,7,8,9},
				{0,1,4,9,6,5,6,9,4,1},
				{0,1,8,7,4,5,6,3,2,9},
				{0,1,6,1,6,5,6,1,6,1},
};
int i,s,x,p,j,k;
int main() {
	f>>k;
	for (j=1;j<=k;j++) {
		f>>n;
		for (i=1;i<=n;i++) {
			x=i;
			p=x%4;
			x=x%10;
			if (p==0) p=4;
			s=s+v[p][x];
			s=s%10;
		}
		g<<s<<'\n';
		s=0;
	}
	return 0;
}