#include <iostream>
using namespace std;
long long int binarySearch(int arr[],int n,int key) {
  int start = 0;
  int end = n-1;
  long long int mid = start + (end-start)/2;
  long long int ans = -1;
while (start <= end){
  long long 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;
}
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 = binarySearch(arr,n,n);
  cout << "square root of " << n << " is " << squareRoot << endl;
  return 0;
}