# -*- coding: utf-8 -*-
"""
While7. n natural soni berilgan (n > 0). Kvadrati n dan katta bo’ladigan eng kichik butun k sonini (k2
> n) aniqlovchi programma tuzilsin. Ildizdan chiqaruvchi funksiyadan foydalanmang.

Created on Tue Jun 29 17:40:59 2021

@author: Mansurjon Kamolov
"""

n=int(input('N='))
if n>0:
    k=1
    while k*k<=n:
        k+=1
    print(k)        
else:
    print('Masala shartiga mos son kiritilmadi! n>0 ')