#include <fstream>
#include <cstring>

#define lmax 105

using namespace std;

ifstream f("cifra.in");
ofstream g("cifra.out");

int i;

int v[lmax];

char s[lmax];

inline int preproc(int x)
{
    int p=x,xx=1;

    while (p)
     if (p%2)
      {
          xx*=x;
          x=(x*x)%10;
          p/=2;
      }
     else
      {
          x=(x*x)%10;
          p/=2;
      }
    return xx;
}

int main()
{
    int t,x;

    for (i=1;i<100;i++)
      v[i]=(v[i-1]+preproc(i))%10;

    f>>t;

    for (i=1;i<=t;i++)
     {
         f>>s;

         x=strlen(s)-1;

         g<<v[(x>1?(s[x-1]-'0'):0)*10+s[x]-'0']<<'\n';
     }

    f.close();
    g.close();
}