#include <cstdio>
#include <cstring>
using namespace std;

int T, Sum[110];
char S[110];

int Calc(int X)
{
    int Last = 1;
    for(int i = 1; i <= X; ++ i)
        Last = (Last * X) % 10;
    return Last;
}

int main()
{
    freopen("cifra.in", "r", stdin);
    freopen("cifra.out", "w", stdout);

    for(int i = 1; i <= 99; ++ i)
        Sum[i] = (Sum[i - 1] + Calc(i)) % 10;

    scanf("%i\n", &T);
    for(; T; T --)
    {
        gets(S + 1);
        S[0] = '0';
        int Len = strlen(S + 1), Nr = (S[Len - 1] - '0') * 10 + S[Len] - '0';

        printf("%i\n", Sum[Nr]);
    }
}