#include <iostream>
#include <stdio.h>
#include <fstream>
#include <cstring>
using namespace std;
FILE *fin=fopen("cifra.in","r");
FILE *fout=fopen("cifra.out","w");;
int u_c_put(long a)
{
    int put=1;
    for(int i=1;i<=a;i++)
        put=put*a%10;
    return put;
}
int t,s;
int nr;
char n[256];
int main()
{
    fscanf(fin,"%d", &t);


    for(int i=1;i<=t;i++)
    {
        //char n1[256];
        fscanf(fin,"%s", &n);
        if(strlen(n)>=2)
            nr=(n[strlen(n)-2]-'0')*10+(n[strlen(n)-1]-'0');
        else
            nr=n[strlen(n)-1]-'0';
        s=0;
        for(int j=1;j<=nr;j++)
            s=(s+u_c_put(j))%10;
        fprintf(fout,"%d\n",s);
        //fout<<s<<'\n';
    }
    return 0;
}