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<math.h>
int main ()
{
    long long int n;
    scanf("%I64d", &n);
    int count=0;
    ///checking prime:
    for(long long  i=2; i*i<=n; i++)
    {
        if (n%i == 0){count++; break ;}
    }
    ///checking prime ends.
    if (count==0){printf("%I64d\n", n-1); return 0;}
    long long  root;
    root = sqrt(n);
    int rem;
   up: rem = n%root;
    if (rem!=0){root++; goto up;}
    else {printf("%d", n/root+root-2);}
    return 0;
}