using namespace std;

#include <iostream>
#include <fstream>
#include <string.h>
#include <stdio.h>

int power(int x,int y){
	x%=10;
	int d=1;
	while(y--)
		d=(x*d)%10;
    return d;
}
/*
int cifra(long long n){
	int s=0;
	while(n){
		s = s + power(n,n)%10;
		--n;
	}
	return s%10;
}
*/
inline int transforma(char s[101]){
	int len=strlen(s);
	if(len==1)
		return s[0]-'0';
	return (s[len-2]-'0')*10+s[len-1]-'0';
}

int main()
{
	int t,s=0,v[21];
	char sir[105];
	int n;
	/*
	v[1]=1;
	for(int i=2;i<=20;++i)
		v[i] = (v[i-1] + power(i,i))%10;
	v[0]=v[20];
	*/
	ifstream f("cifra.in");
	ofstream g("cifra.out");
	f>>t>>ws;
	while(t--){
		f.getline(sir,101);
		n=transforma(sir);
		s=0;
		s+=(n/20)*4;
		n%=20;
		//s+=(cifra(n))%10;
		s+=v[n];
		g<<s%10<<endl;
	}
	return 0;
}