/**
 * Sergey Kopeliovich (burunduk30@gmail.com)
 */

#include <algorithm>
#include <ranges>
#include <iostream>

using namespace std;

#define forn(i, n) for (int i = 0; i < (int)(n); i++)
#define all(a) (a).begin(), (a).end()

// https://codeforces.com/blog/entry/97061
int Sqrt(int64_t x) {
	return *ranges::lower_bound(views::iota(0, 1e9), true, {}, [x](int z) {
		return (int64_t)z * z > x;
	}) - 1; 
}

int main() {
	cout << Sqrt(123) << endl;
}