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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main()
{
    int i,j,f=0;
    long long int a;
    scanf("%lld",&a);

    for(i=2;i<sqrt(a);i++)
        if(a%i==0)
        {
            f=1;
            break;
        }

    if(f)
   {

    for(i=sqrt(a);i>=1;i--)
       {

        for(j=2;j<=a/i;j++)
            if(i*j==a)
              break;
        if(i*j==a)
             break;

       }


   }
        if(f==0)
         printf("%lld",a-1);
        else
            printf("%d",i+j-2);
    return 0;
}