#include<fstream>
#include<cstring>
using namespace std;
ifstream in("cifra.in");
ofstream out("cifra.out");

const int N=1000008;
int v[N],sum[20];

char s[105];

int putere(int n)
{
	int p=1;
	for (int i=0;i<n;i++)
		p=p*n%10;
	return p;
}

void sume()
{
	
	for (int i=1;i<20;i++)
		sum[i]=(sum[i-1]+putere(i))%10;
}

int valoare(char s[101])
{
	if(s[1]=='\0') return s[0] - '0';
	int n = strlen(s);
	return (s[n-2] - '0')*10 + s[n-1] - '0';
}

int main ()
{
	int n, t, r;
	in>>t>>ws;
	sume();
	for(int i=1 ; i<=t ; i++)
	{
		in>>s;
		n = valoare(s);
		r = n/20*4 + sum[n%20];
		r %= 10;
		out<<r<<"\n";
	}
	return 0;
}