#include <iostream>
#include <fstream>
#include <string.h>
using namespace std;

int main() {
	ifstream f("cifra.in");
	ofstream g("cifra.out");
	
	int n, sol, i, j, putere, nr;
	string s;
	
	
	f>>n;
	f.get();
	while(n--) {
		getline(f,s);		
		int dim = s.size();
		
		nr = 0;
		if(dim >= 2) nr = int(s[dim - 2]) - 48;
		nr = nr * 10 + int(s[dim-1]) - 48;
		
		sol = 0;
	
		for(i = 1; i<=nr; i++) {
			putere = 1;
			for(j=1; j<=i; j++) putere = (putere * i) % 10;
			sol = (sol+putere)%10;
		}	
		
		g<<sol<<"\n";
	}
	
	return 0;	
}