#include <iostream>
#include <math.h>
#include <fstream>
#include <strings.h>

using namespace std;

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

int n, k, suma, T;
char numar[1000000000];
int sumaF(int n){

    int aux = n%10;
    if(n<=k){
        suma = suma + int(pow(aux,n))%10;
        return sumaF(n+1);
    }else{
        out<<suma%10<<endl;
        return 0;
    }
}

int main()
{
    int i,j;
    in>>T;
    for(i=1;i<=T;i++){
        k = 0;
        suma = 0;
        in>>numar;
        for(j=0;j<strlen(numar);j++){
            k = k * 10 + (numar[j] - 48);
        }
        sumaF(1);
        //out<<k<<endl;
    }
}