#include<fstream>
using namespace std;
int z,n,sum;
string s;
int main()
{
    ifstream f("cifra.in");
    ofstream g("cifra.out");
    f>>n;
    for(int i=1;i<=n;i++)
    {
        f>>s;
        sum=0;
        if(s.size()==1)z=0;
           else  z=s[s.size()-2]-'0';
           z++;
       for(int j=1;j<=s[s.size()-1]-'0';j++)
       {
           if(j==1)sum+=z;
           if(j==2&&z%2==1)sum+=4;
           if(j==3&&z%2==1)sum+=7;
           if(j==4)sum+=(z*6)%10;
           if(j==5)sum+=(z*5)%10;
           if(j==6)sum+=(z*6)%10;
           if(j==7&&z%2==1)sum+=3;
           if(j==8&&z%2==1)sum+=6;
           if(j==9)sum+=(z*9)%10;
       }
       sum%=10;z--;
       for(int j=s[s.size()-1]-'0'+1;j<=9;j++)
       {
           if(j==1)sum+=z;
           if(j==2&&z%2==1)sum+=4;
           if(j==3&&z%2==1)sum+=7;
           if(j==4)sum+=z*6;
           if(j==5)sum+=z*5;
           if(j==6)sum+=z*6;
           if(j==7&&z%2==1)sum+=3;
           if(j==8&&z%2==1)sum+=6;
           if(j==9)sum+=z*9;
       }

        sum%=10;
       g<<sum<<"\n";
    }
    return 0;
}