#include<fstream>
using namespace std;
int t,n[30001],uc;
void ultima(int x){
int c,d;
c=x%10;
d=x%100;
if(c%5==0||c==6||c==0||c==1)uc=c;
if(c==4)uc=6;
if(c==2){if(d%4==2)uc=4;
if(d%4==0)uc=6;}
if(c==9){if(d%2==1)uc=9;
if(d%2==0)uc=1;}
if(c==3){if(d%4==1)uc=3;
if(d%4==2)uc=9;
if(d%4==3)uc=7;
if(d%4==0)uc=1;}
if(c==7){if(d%4==1)uc=7;
if(d%4==2)uc=9;
if(d%4==3)uc=3;
if(d%4==0)uc=1;}
if(c==8){if(d%4==1)uc=8;
if(d%4==2)uc=4;
if(d%4==3)uc=2;
if(d%4==0)uc=6;}
}
ifstream f("cifra.in");
ofstream g("cifra.out");
int main(){
int i,j,s[30001],z[30001];
f>>t;
for(i=1;i<=t;i++)
f>>n[i];
for(i=1;i<=t;i++)
for(j=1;j<=n[i];j++)
{ultima(j);s[i]=s[i]+uc;}
  f.close();
    for(i=1;i<=t;i++)
        {uc=s[i]%10;g<<uc<<"\n";}
    g.close();
return 0;}