Stack 

Stack is a container of elements that are inserted and deleted according to LIFO (Last In First Out). 

For n stack Si (i=0,1,...,n−1), perform a sequence of the following operations. 

push(t, x): Insert an integer x to St. 

top(t): Report the value which should be deleted next from St. If St is empty, do nothing. 

pop(t): Delete an element from St. If St is empty, do nothing. 

In the initial state, all stacks are empty.

The input is given in the following format. nq query1 query2 : queryq Each query queryi is given by 0 t x or 1 t or 2 t where the first digits 0, 1 and 2 represent push, top and pop operations respectively. 1≤n≤1,000 1≤q≤200,000 −1,000,000,000≤x≤1,000,000,000 Sample Input 1

For each top operation, print an integer in a line.

3 9
0 0 1
0 0 2
0 0 3
0 2 4
0 2 5
1 0
1 2
2 0
1 0

3
5
2