#include <iostream>
#include <fstream>
#include <string.h>
using namespace std;
ifstream fin("cifra.in");
ofstream fout("cifra.out");

int vuni[]={0,1,4,7,6,5,6,3,6,9,0};
int vimp[]={0,1,6,3,6,5,6,7,4,1,0};
int vpar[]={0,1,4,7,6,5,6,3,6,9,0};


int main()
{char s[101];
int t;
fin>>t;
fin.get();
while(t--)
{
    fin.getline(s,101);
int i,rez=0;
int lg=strlen(s);
if(lg==1)for(i=0;i<=s[0]-'0';i++)rez+=vuni[i];
if(lg>1)
{int cif=s[lg-2]-'0';
rez=((cif+1)/2)*7 + (cif/2)*9;
if(cif%2)
    for(i=1;i<=s[lg-1]-'0';i++)rez+=vimp[i];
else
    for(i=1;i<=s[lg-1]-'0';i++)rez+=vpar[i];
}
fout<<rez%10<<'\n';
}

}