Write a function reverse_dict(d) that swaps the keys and values of a dictionary. Assume all values are unique.

INPUT FORMAT

First line contains an integer $N (N <= 100)$ From the second line to the $N + 1$ line, each line contains a key and a value, separated by a blank space.

OUTPUT FORMAT

Ouput $N$ lines, each line contains a key and a value, separated by a blank space. The key should be outputed in the dictionary order.

SAMPLE

INPUT

3
a c
b d
c e

OUTPUT

c a
d b
e c