#include<fstream>
#include<iostream>
#include<cmath>
#include<cstring>

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

int c2(int x, long long k){
    int rest = k%4;
    if (rest == 0) {rest = 4;}
    rest = (int)(pow((double)x, (double)(rest%4)))%10;
    return rest;
}

int main(){
    char n[105];
    int c,T;
    char denis;
    f>>T;
    f.get(denis);
    for(int j=1;j<=T;j++){
        f.getline(n,105);
        int s=0;
        c=strlen(n);
        int v;
        if(c==1)
        {
            v=(n[c-1]-'0');
        }
        else
        {
            int c1=c;
            v=0;
            while (c1>0)
            {
                v = v * 10 + (n[c1-1]-'0') ;
                c1--;
            }
        }
        for(long long i=1;i<=v;i++)
        {
            int u=i%10;
            s=s+c2(u,i);
            s=s%10;
        }
        g<<s%10<<endl;
    }
}