#include <math.h>
#include <fstream>
#define MAX 1500000
using namespace std;
    ifstream f1 ("cifra.in");
    ofstream f2 ("cifra.out");
    int u2[4] = {6, 2, 4, 8};
    int u3[4] = {1, 3, 9, 7};
    int u4[2] = {6, 4};
    int u7[4] = {1, 7, 9, 3};
    int u8[4] = {6, 8, 4, 2};
    int u9[2] = {1, 9};
int u(int x){
    switch(x){
        case 0:
            return 0;
        case 1:
            return 1;
        case 2:
            return u2[x%4];
        case 3:
            return u3[x%4];
        case 4:
            return u4[x%2];
        case 5:
            return 5;
        case 6:
            return 6;
        case 7:
            return u7[x%4];
        case 8:
            return u8[x%4];
        case 9:
            return u9[x%2];
    }
}
int main(){
    long t, i;
    long long n, j;
    int sum;
    f1>>t;
    for(i = 0; i < t; i++){
        f1>>n;
        for(j = 1, sum = 0; j <= n; j++, sum %= 10){
            sum += u(j%10);
        }
        f2<<sum<<"\n";
    }
    return 0;
}