The capital of the United States, Washington DC, was first established hundreds of years ago. At first, not all land was connected - all pieces of land were actually surrounded by water and were inaccesible from one another without sailing. Over time, more and more 2-way roads have been built over water (e. g. bridges). At the same time, some of these roads were also destroyed (e.g. during wars) or otherwise made inaccesible (e.g. floods, earthquakes, landslides). A historian builds a record of all roads that were ever built or destroyed - chronologically. He also sometimes asks - were land X and land Y connected by roads at this point in time? He begs you for help in answering his queries.
Input data
In order to help you, the historian has assigned a unique number to each piece of land. There are such pieces, indexed from to . His record also contains entries. The first line contains integers and , followed by entries - each on a new line. Each such entry will have one of the following three types:
+ a b
: A road between a and b has been built. It is guaranteed it didn't already exist.- a b
: The road between a and b has been destroyed. It is guaranteed it existed.? a b
: Can you reach land b from land a without sailing?
Output data
For each query of type , output a line or indicating whether and were connected.
Constraints and clarifications
Example 1
stdin
300 5
? 23 37
+ 23 37
? 23 37
- 37 23
? 23 37
stdout
N
Y
N
Example 2
stdin
4 10
+ 1 2
+ 2 3
+ 3 1
? 1 4
+ 4 3
? 1 4
- 2 3
? 1 4
- 1 3
? 1 4
stdout
N
Y
Y
N