#include <bits/stdc++.h>
#define NMAX 110
using namespace std;
ifstream in("cifra.in");ofstream out("cifra.out");
int V[NMAX],T;
char S[NMAX],c;


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


void generare() {
    for(int i = 1; i < 100; i++) {
        V[i] = (V[i-1] + ultimaCifra(i)) % 10;
    }
}

int main() {
    generare();

    in >> T;
    for(int i = 1; i <= T; i++) {
        in.get(c);
        in.get(S,NMAX);
        int nr = 0, L = strlen(S);
        if(L == 1) {
            nr = S[L - 1] - '0';
        } else {
            nr = (S[L - 1] - '0') + (S[L - 2] - '0') * 10;
        }
        out << V[nr] << '\n';
    }

    in.close();out.close();

    return 0;
}