import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int t = sc.nextInt();
    for(int i = 0; i < t; i++) {
      String s = sc.next();
      while(s.length() > 1) {
        String q = "";
        for(int j = 0; j < s.length() - 1; j++) {
          int a = Integer.parseInt(String.valueOf(s.charAt(j)));
          int b = Integer.parseInt(String.valueOf(s.charAt(j + 1)));
          int c = a + b;
          if(c > 9) c = (c % 10) + 1;
          q += c; 
        }
        s = q;
      }
      int ans = Integer.parseInt(String.valueOf(s.charAt(0)));
      System.out.println(ans);
    }
  }
}