#include<fstream>
#include<iostream>
#include<math.h>
#include<cstring>
 
using namespace std;
ifstream f("cifra.in");
ofstream g("cifra.out");
 
int c2(int x, long long k){
    if(k%4==0) return x*x*x*x%10;
    if(k%4==1) return x%10;
    if(k%4==2) return x*x%10;
    if(k%4==3) return x*x*x%10;
}
 
int main(){
    char n[105];
    int c,T;
    char denis;
    f>>T;
    f.get(denis);
    for(int j=1;j<=T;j++){
        f.getline(n,105);
        int s=0;
        c=strlen(n);
        int v;
        if(c==1) 
	{
  		v=(n[c-1]-'0');
	}
 	else 
	{
		int c1=c;
		v=1;
		while (c1) 
 
		{

			v=v*10 + (n[c1-1]-'0') ;

			c1--;
		}	
	}
        for(long long i=1;i<=v;i++)
	{
        	int u=i%10;
		s=s+c2(u,i);
		s=s%10;
        }
        g<<s%10<<endl;
    }
}