def migratoryBirds(arr):
    freq = [0 for _ in range(6)]
    
    for i in range(len(arr)):
        freq[arr[i]] += 1
        
    max_freq = 0
    max_freq_id = None
    for x in range(len(freq)):
        if freq[x] > max_freq:
            max_freq = freq[x]
            max_freq_id = x
            
    return max_freq_id