#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
char s[150];
int main()
{
    freopen("cifra.in","r",stdin);
    freopen("cifra.out","w",stdout);
    int n,i,nr,num,sum,j,x,k;
    scanf("%d ",&n);
    for(i=1; i<=n; i++)
    {
        gets(s);
        num=strlen(s);
        nr=0;
        if(num==1)
          nr=s[0]-'0';
        else
          nr=(s[num-2]-'0')*10+s[num-1]-'0';
        sum=0;
        for(j=1; j<=nr; j++)
            {
                x=j%10;
                num=1;
                for(k=1; k<=4+j%4; k++)
                    num=(num*x)%10;
            sum=(sum+num);
            }
        printf("%d\n",sum%10);
    }
    return 0;
}