Geek wants to scan N documents using two scanners. If S1 and S2 are the time taken by the scanner 1 and scanner 2 to scan a single document, find the minimum time required to scan all the N documents. You can use one or more scanners at a time.
Example 1:
Input: 
S1 = 2, S2 = 4, N = 2
Output: 4
Explaination: Here we have two possibilities. 
Either scan both documents in scanner 1 or
scan one document in each scanner. 
In both the cases time required is 4.
 
Example 2:
Input: 
S1 = 1, S2 = 3, N = 2
Output: 2
Explaination: Here the optimal approach is to 
scan both of them in the first scanner.
 
Your Task:
You do not need to read input or print anything. Your task is to complete the function minTime() which takes S1, S2 and N as input parameters and returns the minimum tme required to scan the documents.
 
Expected Time Complexity: O(logN)
Expected Auxiliary Space: O(1)
 
Constraints:
1 ≤ S1, S2, N ≤ 10^{6}
1 ≤ S1*N, S2*N ≤ 10^{9}