The Smart Beaver has recently designed and built an innovative nanotechnologic all-purpose beaver mass shaving machine, "Beavershave 5000". Beavershave 5000 can shave beavers by families! How does it work? Very easily! 
There are 
n beavers, each of them has a unique id from 1 to 
n. Consider a permutation 
a1,a2,...,an of 
n these beavers. Beavershave 5000 needs one session to shave beavers with ids from 
x to 
y (inclusive) if and only if there are such indices 
i1<i2<...<ik, that 
ai1=x, 
ai2=x+1, ..., 
aik-1=y-1, 
aik=y. And that is really convenient. For example, it needs one session to shave a permutation of beavers 
1,2,3,...,n. 
If we can't shave beavers from 
x to 
y in one session, then we can split these beavers into groups 
[x,p1], 
[p1+1,p2], ..., 
[pm+1,y] (x≤p1<p2<...<pm<y), in such a way that the machine can shave beavers in each group in one session. But then Beavershave 5000 needs 
m+1 working sessions to shave beavers from 
x to 
y. 
All beavers are restless and they keep trying to swap. So if we consider the problem more formally, we can consider queries of two types: 
			
				- 
					what is the minimum number of sessions that Beavershave 5000 needs to shave beavers with ids from x to y, inclusive?
				
- 
					two beavers on positions x and y (the beavers ax and ay) swapped.
				
You can assume that any beaver can be shaved any number of times.