#include <cstdio>
#include<string.h>
#define MAX 100
using namespace std;
char sir[MAX+1];
int cif1[11]={0,1, 4, 7, 6, 5, 6, 3, 6, 9, 0};
int cif2[11]={0,1, 6, 3, 6, 5, 6, 7, 4, 9, 0};
int main()
{
    freopen("cifra.in", "r", stdin);
    freopen("cifra.out", "w", stdout);
    int t, uc, i, n, u, s=0, j;
    scanf("%d\n", &t);
    for(j=1;j<=t;j++)
    {
        s=0;
        gets(sir);
        n=strlen(sir);
        uc=sir[n-1]-'0';
        u=0;
        if(n-2>=0)
            u=sir[n-2]-'0';
        u*=6;
        s+=u;
        s%=10;
        if(u%2==1)
            for(i=0;i<=uc;i++)
                s=(s%10+cif2[i])%10;
        else
            for(i=0;i<=uc;i++)
                s=(s%10+cif1[i])%10;
        printf("%d\n", s);
    }
    return 0;
}