Given a number N.Find the minimum sum of its factors.

Example 1:

Input:
N=10
Output:
7
Explanation:
There are two ways to factories N, which are
10=1*10(sum=10+1=11)
10=2*5(sum=2+5=7)
Thus, the answer is 7.

Example 2:

Input:
N=12
Output:
7
Explanation:
There are  ways to factorise N, which are
12=12*1(sum=12+1=13)
12=3*4(sum=3+4=7)
12=6*2(sum=6+2=8)
12=2*3*2(sum=2+3+2=7).

Your Task:
You don't need to read input or print anything. Your task is to complete the function sumOfFactors() which takes a number N as an input parameter and returns the minimum sum of its factors.

Expected Time Complexity:O(N^1/2)
Expected Auxillary Space:O(1)

Constraints:
1<=N<=10⁵