#include <cstdio>
#include <cctype>

using namespace std;

int p[] = {0,1,5,2,8,3,9,2,0,1,1,2,4,3,7,2,8,7,9,0};

int main(){
    FILE *fin, *fout;
    int t,i,nr,suma;
    char ch;
    fin = fopen("cifra.in","r");
    fscanf(fin,"%d\n",&t);
    fout = fopen("cifra.out","w");
    for (i=0;i<t;i++) {
        ch = fgetc(fin);
        nr = 0;
        while (isdigit(ch)) {
            if (nr > 9)
                nr = nr % 10 * 10 + ch - '0';
            else
                nr = nr * 10 + ch - '0';
            ch = fgetc(fin);
        }
        suma = p[19] * (nr / 20) % 10 + p[(nr - 1) % 20 + 1];
        suma %= 10;
        fprintf(fout,"%d\n",suma);
    }
    fclose(fin);
    fclose(fout);
    return 0;
}