"""
"""
import heapq
from collections import Counter

def top_k_frequent(nums, k):
    count = Counter(nums)
    return heapq.nlargest(k, count.keys(), key=count.get)

# Example usage
nums = [1, 1, 1, 2, 2, 3]
k = 2
print(top_k_frequent(nums, k))  # Output: [1, 2]