#include<stdio.h>

int cif[10][10];

int main() {
    freopen("cifra.in", "r", stdin);
    //freopen("cifra.out", "w", stdout);
    
    int i;
    for (i = 0; i < 10; i++) {
        cif[i][0]++;
        cif[i][1] = i;
        do {
            cif[i][0]++;
            cif[i][cif[i][0]] = (cif[i][cif[i][0]-1] * i) % 10;
        } while(cif[i][1] != cif[i][cif[i][0]]);
        cif[i][0]--;
    }

    int t, n, nr, j;

    scanf("%d", &t);

    for (i = 0; i < t; i++) {
        scanf("%d", &n);
        nr = 0;

        for (j = 1; j <= n; j++) {
            int b = j % 10;
            int ind = j % cif[b][0];
            int exp;
            if (ind == 0)
                exp = cif[b][cif[b][0]];
            else
                exp = cif[b][ind];
            nr = (nr + exp) % 10;
        }

        printf("%d\n", nr);
    }

    return 0;
}