#include    <iostream>
#include    <fstream>

using namespace std;

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

int i,j,n,m;

#define     ll  long long

long long suma;

long long rez2(ll x){
    ll y, h;
    ll rez;
    y = x;
    x %= 10;
    if(x == 0) return 0;
    if(x == 1) return 1;
    if(x == 2){
        h = y % 4;
        if(h == 1) return 2;
        if(h == 2) return 4;
        if(h == 3) return 8;
        if(h == 0) return 6;
    }
    if(x == 3){
        h = y % 4;
        if(h == 1) return 3;
        if(h == 2) return 9;
        if(h == 3) return 7;
        if(h == 0) return 1;

    }
    if(x == 4){
        h = y % 2;
        if(h == 1) return 4;
        if(h == 0) return 6;
    }
    if(x == 5) return 5;
    if(x == 6) return 6;
    if(x == 7){
        h = y % 4;
        if(h == 1) return 7;
        if(h == 2) return 9;
        if(h == 3) return 3;
        if(h == 4) return 1;
    }
    if(x == 8){
        h = y % 4;
        if(h == 1) return 8;
        if(h == 2) return 4;
        if(h == 3) return 2;
        if(h == 0) return 6;
    }
    if(x == 9){
        h = y % 2;
        if(h == 1) return 9;
        if(h == 2) return 1;
    }
  //  return rez;
}

int main()
{
    j = 0;
    f >> m;
    while(j < m){
        f >> n;
        j++;
        suma = 0;
        for(int i = 1; i <= n; ++i)
            suma+=rez2(i) % 10;
        g << suma % 10 << "\n";
    }
    //getch();
    f.close();
    g.close();
    return 0;
}