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 Python (3.4.3) (judge verdict: Wrong Answer)

n = int(input())
factor = []
tmp = n
for i in range(2, int(-(-n ** 0.5 // 1)) + 1):
    while tmp % i == 0:
        factor.append(i)
        tmp //= i
if tmp != 1:
    factor.append(tmp)
if len(factor) == 0:
    factor.append(n)
if len(factor) == 1:
    print(factor[0] - 1)
else:
    a, b = 1, 1
    for i in sorted(factor, reverse=True):
        if a < b:
            a *= i
        else:
            b *= i
    print(a + b - 2)