#include <fstream>
#include<cstring>
#include<cstdlib>

using namespace std;

ifstream f("cifre.in");
ofstream g("cifre.out");
int main()
{

long i,T,us,up,j;
long unsigned N;
char a[255];

f>>T;
for(i=1;i<=T+1;i++)
{
f>>a;
//unsigned long N = ((unsigned)atol(a));
N=atol(a);

  us=0;
for(i=1;i<=N;i++)
{
  up=1;
 for(j=1;j<=i;j++)
  up=up*i%10;
 us=(us+up)%10;
}
g<<us<<endl;

}

    return 0;
}