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>

int main()
{
    long long n,i,maxi,maxj,max;
    scanf("%lld",&n);
    maxi = maxj = max = n;

    for (i = 1; i*i <= n; i++)
    {
        if(n % i == 0)
        {
            if(i * i != n){
                if(max > i - 1 + (n / i) - 1){
                    max = i - 1 + (n / i) - 1;
                    maxi = i;
                    maxj = n / i;
                }
            }
        }
    }
    printf("%lld",(maxi - 1) + (maxj - 1));
}