import sys
from collections import Counter
from itertools import accumulate

def main():
    n, k = map(int, sys.stdin.readline().split())
    a = list(map(int, sys.stdin.readline().split()))
    freq = Counter(a)
    freqs = sorted(freq.values(), reverse=True)
    prefix = list(accumulate(freqs, initial=0))  # prefix[0]=0, prefix[1] = freqs[0], etc.

    low = 1
    high = len(freqs)
    ans = high  # Initialize with the maximum possible value

    while low <= high:
        mid = (low + high) // 2
        if mid >= len(prefix):
            continue  # This case shouldn't happen due to high being len(freqs)
        if prefix[mid] >= k:
            ans = mid
            high = mid - 1
        else:
            low = mid + 1
    print(ans)

if __name__ == "__main__":
    main()