#include <iostream>
using namespace std;
int sqrt(int arr[], int n, int key) {
  int start = 0;
  int end = n - 1;
  int mid = start + (end - start) / 2;
  int ans = -1;
  while (start <= end) {
    int square = mid * mid;
    if (square == key) {
      return mid;
    } else if (square > key) {
      end = mid - 1;
    } else {
      start = mid + 1;
      ans = mid;
    }
    mid = start + (end - start) / 2;
  }
  return ans;
}
double precision(int n, int precision, int integer) {
  double factor = 1;
  double ans = integer;
  for (int i = 0; i < precision; i++) {
    factor = factor / 10;
    for (double j = ans; j * j < n; j += factor) {
      ans = j;
    }
  }
  return ans;
}
int main() {
  int n;
  cout << "enter the number :" << endl;
  cin >> n;
  int arr[n];
  for (int i = 0; i < n; i++) {
    arr[i] = (i + 1);
  }
  int squareRoot = sqrt(arr, n, n);
  double finalAns = precision(n, 3, squareRoot);
  cout << "square root of " << n << " is " << finalAns << endl;
  return 0;
}