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(void){
  int n,i,j,a,b,count=0;
  scanf("%d",&n);
   for(i=2;i<n;i++){
    if(n%i==0){
        a=n/i;
        b=i;
        if(a==b) break;
        if(a==10) break;
    }
   }
   printf("a=%d\n",a);
   printf("b=%d\n",b);
   for(i=2;i<=a;i++){
    count++;
   }
   for(i=2;i<=b;i++){
    count++;
   }
   printf("%d\n",count);
   return 0;
}