#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int uc[101];
int cifra(int x)
{
    unsigned long long int i,s=1;
    for (i=1; i<=x; i++)
    {
       s*=x % 10;
    }
    return s % 10;
}
int main()
{
    FILE *pf,*pg;
    pf=fopen("cifra.in","r");
    pg=fopen("cifra.out","w");

    int n,i;
    char c[100000];
    fscanf(pf,"%d",&n);
    for (i=1; i<=100; i++)
        uc[i]=(uc[i-1]+cifra(i)) % 10;
    while (n>0)
    {
        fscanf(pf,"%s",c);
        if (strlen(c)==1)
            fprintf(pg,"%d\n",uc[c[0]-'0']);
        else
            fprintf(pg,"%d\n",uc[(c[strlen(c)-2]-'0')*10+c[strlen(c)-1]-'0']);
        n--;
    }
    return 0;
}