#include <stdio.h>
int ucf[20],t;


int putere(int x,int y)
{
        int p;
        int i;
        p=1;
        for (i=1;i<=y;i++)
                {
                        p=(p*x) % 10;
                }
        return p;
}


void precalculare(void)
{
        int i;
        ucf[0]=0;
        for (i=1;i<=19;i++)
                ucf[i]=(ucf[i-1]+putere(i,i)) % 10;
}



void iofile(void)
{
        int c;
        freopen("cifra.in","r",stdin);
        freopen("cifra.out","w",stdout);
        scanf("%d",&t);
        c=getchar();
}



void prel(void)
{
        int c;
        int uc,luc,res;
        uc=luc=0;
        while ((c=getchar())!='\n')
                {
                       luc=uc;
                       uc=c-'0';
                }
        luc=(luc % 2);
        res=(luc*ucf[19]+ucf[luc*10+uc]) % 10;
        printf("%d\n",res);
}


int main(void)
{
        int i;
        precalculare();
        iofile();
        for (i=1;i<=t;i++)
                {
                        prel();
                }
        fclose(stdin);
        fclose(stdout);
        return 0;
}