#include<fstream> 

using namespace std; 

ifstream in ("cifra.in");


int citeste ()
{ 
	char sir[105]; 
	int n; 
	in>>sir; 
	n=strlen (sir); 
	if(n==1) 
		return sir[0]-'0';
	return sir[n-1]-'0'+(sir[n-2]-'0')*10; 
} 

int putere (int a,int b) 
{ 
	int i,p=1;
	for(i=1;i<=b;i++) 
		p=p*a%10;
	return p; 
} 

int main ()
{ 
	int s=0,i,n; 
	ofstream out("cifra.out"); 
	int t;
	in>>t;
	while(t--)
	{
		n=citeste();
		s=0;
		for(i=1;i<=n;i++) 
			s=s+putere(i,i); 
		out<<s%10<<"\n"; 
	}
	in.close();
	out.close();
	return 0; 
}