#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;

char numar[110];
const int u[11]={0,1,5,2,8,3,9,2,8,7,7};
const int sapte[11]={0,7,4,1,8,5,2,9,6,3};//sapte[i]=(i*7)%10;
int main(){
  int T;
  ifstream fin("cifra.in");
  ofstream fout("cifra.out");
  fin>>T;
  int i; 
  int n;
  for(i=0;i<T;i++){
     fin>>(numar+1);//ca sa ma asigur ca am cel putin doua cifre
     numar[0]='0';
     n=strlen(numar);
     fout<<(sapte[(numar[n-2]-'0')]+u[numar[n-1]-'0'])%10<<'\n';
  }
return 0;
}