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)

import math

N = int(input())

a = pow(10,12)

is_not_prime = False
#for k in range(2, int(math.sqrt(N)) + 1):
#    if N % k == 0:
#        is_not_prime = True
#        break
#if is_not_prime:
for i in range(1, int(math.sqrt(N))):
    print(i)
    j = N/i
    if j.is_integer():

        if (i+int(j)) < a:
            a = i+int(j)
    #if j < 2:
    #    break

print(a - 2)
#else:
#    print(N - 1)