import math
 
def is_square(n):
    root = int(math.sqrt(n))
    return root * root == n
 
def count_non_square_numbers(n):
    count = 0
    for i in range(1, n + 1):
        if not is_square(i):
            count += 1
    return count
 
def find_kth_non_square_number(k):
    start = 1
    end = k * 2
    while start < end:
        mid = (start + end) // 2
        if count_non_square_numbers(mid) >= k:
            end = mid
        else:
            start = mid + 1
    return start
 
# 입력 받기
K = int(input())
 
# K번째 제곱ㄴㄴ수 찾기
result = find_kth_non_square_number(K)
 
# 결과 출력
print(result)
 

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MQ==

1