sum range

  vector < ll > v(2e5+1) ;
  v[0] = 0 , v[1] = 1 ;
  for(int i = 2 ; i <= 2e5 ; i++) v[i] = (v[i-1] % 10 + v[i-2] % 10) % 10 ;
  for(int i = 1; i < v.size(); i++)  v[i] += v[i-1];
  ll q ;
  cin >> q ;
  while(q--){
      ll n, m;
      cin >> n >> m;
      cout << (v[m] - v[n-1]) % 10 << "\n";
  }