input: Write a python function to count the number of As, Bs, Cs, and Ds from student scores.
  assert get_grade_counts([{"name": "Alice", "scores": [95, 85, 75, 65]}, {"name": "Bob", "scores": [90, 80, 70, 60]}]) == {"As": 2, "Bs": 2, "Cs": 2, "Ds": 2}
  assert get_grade_counts([{"name": "Charlie", "scores": [100, 82, 77]}, {"name": "David", "scores": [59, 92, 88]}]) == {"As": 2, "Bs": 2, "Cs": 1, "Ds": 1}
  assert get_grade_counts([{"name": "Eve", "scores": [91, 81, 71]}, {"name": "Frank", "scores": [89, 79, 69]}]) == {"As": 1, "Bs": 2, "Cs": 1, "Ds": 2}
output: def get_grade_counts(students):
      grade_counts = {"As": 0, "Bs": 0, "Cs": 0, "Ds": 0}
      for student in students:
          for score in student["scores"]:
              if score >= 90:
                  grade_counts["As"] += 1
              elif score >= 80:
                  grade_counts["Bs"] += 1
              elif score >= 70:
                  grade_counts["Cs"] += 1
              elif score >= 60:
                  grade_counts["Ds"] += 1
      return grade_counts