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

int main() {
	string line;
	int n,a,b,c;
	int s[101];
	int x[11][5] = {{0},{1},{6,2,4,8},{1,3,9,7},{6,4},{5},{6},{1,7,9,3},{6,8,4,2},{1,9}};
	int y[] = {1,1,4,4,2,1,1,4,4,2};
	ifstream myfile("cifra.in");
	ofstream outfile("cifra.out");

	s[0] = 0;
	c = 0;

	getline(myfile,line);
	n = atoi(line.c_str());
   	for (int i = 1; i<=n; i++) {
   		getline(myfile,line);
   		if(line.length()>2)
   			a = atoi(line.substr(line.length()-2).c_str());
   		else
   			a = atoi(line.c_str());
   		while(c <= a) {
   			c++;
   			b = c % 10;
   			s[c] = (s[c-1] + x[b][c%y[b]])%10;
   		}
   		outfile<<s[a]<<"\n";
   	}

   	myfile.close();
   	outfile.close();
	return 0;
}