#include <iostream>
#include <fstream>
#include <string>

using namespace std;

string n;

int last[10][2];
int results[100];

int solve(unsigned long long i);

void init()
{
  last[1][0] = 1; last[1][1] = 1;
  last[2][0] = 4; last[2][1] = 6;
  last[3][0] = 7; last[3][1] = 3;
  last[4][0] = 6; last[4][1] = 6;
  last[5][0] = 5; last[5][1] = 5;
  last[6][0] = 6; last[6][1] = 6;
  last[7][0] = 3; last[7][1] = 7;
  last[8][0] = 6; last[8][1] = 4;
  last[9][0] = 9; last[9][1] = 9;

  for(int i = 1; i < 100; ++i)
  {
    results[i] = solve(i);
  }
}

int transform()
{
  int nval = 1;
  if(n.length() < 3)
    nval = stoi(n);
  else
    nval = int(n[n.length() - 2]  - '0') * 10+ int(n[n.length() - 1] - '0');
  return nval;
}

int howMany(int i, int z)
{
  int nval = transform();
  return (nval - 10 * z - i) / 20 + (i + 10 * z <= nval);
}

int solve()
{
  int result = 0;
  for(int i = 1; i <= 9; ++i)
  {
    result += howMany(i, 0) * last[i][0] + howMany(i, 1) * last[i][1];
    result %= 10;
  }
  return result;
}

int solve(unsigned long long i)
{
  n = to_string(i);
  return solve();
}

int main()
{
  freopen("cifra.in", "r", stdin);
  freopen("cifra.out", "w", stdout);

  int t;
  cin >> t;
  init();
  for(int i = 0; i < t; ++i)
  {
    cin >> n;
    cout << results[transform()] << '\n';
  }

  return 0;
}