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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