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: Wrong Answer)

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



int main()
{
  long  a;
  scanf("%ld",&a);

  getchar();
  if(a==1){
    printf("0\n");
  }else
  {
       long rn=0;
       while (rn*rn<=a) rn++;
       long re;
       for(long  i=2;i<=rn;i++){
        if(!(a%i)){
            long  temp = (a/i -1) +(i-1);
            if(temp<re){
                re = temp;
            }
        }
       }
       printf("%ld\n",re);
  }
  return 0;
}