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: Runtime Error)

#include <bits//stdc++.h>
#define rep(i,k) for(int i=0;i<k;i++)
#define int unsigned long long
using namespace std;
signed main(void){
    int n,m,a,b,c,ans;
    cin>>n;
    
    for(int i=1;i<n;i++){
        if(i*i>n){
        ans=i;
        break;
        }
    }
    
    for(int i=ans;i>0;i--){
        if(n%i==0){
            b=i;
            break;
        }
    }
    
    cout<<n/b+b-2<<endl;
}