Problem:
Score : 300 points

Problem Statement

Takahashi is standing on a multiplication table with infinitely many rows and columns.

The square (i,j) contains the integer i \times j. Initially, Takahashi is standing at (1,1).

In one move, he can move from (i,j) to either (i+1,j) or (i,j+1).

Given an integer N, find the minimum number of moves needed to reach a square that contains N.

Constraints

2 \leq N \leq 10^{12}

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

Print the minimum number of moves needed to reach a square that contains the integer N.

Sample Input 1

10

Sample Output 1

5

(2,5) can be reached in five moves. We cannot reach a square that contains 10 in less than five moves.

Sample Input 2

50

Sample Output 2

13

(5, 10) can be reached in 13 moves.

Sample Input 3

10000000019

Sample Output 3

10000000018

Both input and output may be enormous.

Solution in C (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#include<math.h>


//qsort(pa,n,sizeof(int),(int(*)(const void* ,const void*))cmp);


int main(void){

  long long n;
  scanf("%lld",&n);
  long long i,j,k;
  long long max=1;
  long long ano;
  //素数の時
  /*for(i=2;i<n;i++){
    if(n%2==0)
    break;
  }
  if(i==n){
    printf("%lld",n-1);
    return 0;
  }*/

  for(i=2;i*i<=n;i++){
    if(n%i==0)
    max=i;
  }
  if(n==3){
    printf("%d",2);
    return 0;
  }
  if(n==2){
    printf("%d",1);
    return 0;
  }



  ano=n/max;

  printf("%lld",max+ano-2);


  return 0;
}