You are given N elements and your task is to Implement a Stack in which you can get minimum element in O(1) time.

Example 1:

Input:
push(2)
push(3)
pop()
getMin()
push(1)
getMin()
Output: 3 2 1
Explanation: In the first test case for
query 
push(2)  the stack will be {2}
push(3)  the stack will be {2 3}
pop()    poped element will be 3 the
         stack will be {2}
getMin() min element will be 2 
push(1)  the stack will be {2 1}
getMin() min element will be 1

Your Task:
You are required to complete the three methods push() which take one argument an integer 'x' to be pushed into the stack, pop() which returns a integer poped out from the stack and getMin() which returns the min element from the stack. (-1 will be returned if for pop() and getMin() the stack is empty.)

Expected Time Complexity : O(1) for all the 3 methods.
Expected Auixilliary Space : O(1) for all the 3 methods.

Constraints:
1 <= Number of queries <= 100
1 <= values of the stack <= 100