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 Pascal (FPC 2.6.2) (judge verdict: Wrong Answer)

uses crt;
var
        b,a,min:qword;
        i,j,n:int64;
        ok:boolean;
begin
        clrscr;
        read(n);
        if n mod 2<>0 then begin write(n-1); exit; end
        else
        for i:=n div 2 downto 1 do
        begin
        if ok=true then break;
                for j:=3 to n div 2 do
                        if i*j=n then begin min:=(i-1)+(j-1); ok:=true; break; end; end;
        for i:=(n div 2)+1 downto 1 do
                for j:=3 to n div 2 do
                        if i*j=n then begin b:=(i-1)+(j-1); if min>b then min:=b; end;
         if min>0 then write(min) else write(n div 2);
         readln;
         readln;
end.