Problem Statement

We have a sequence $X$, which is initially empty. Takahashi has performed the following operation for $i=1,2,\ldots,N$ in this order.

• Append $l_i,l_i+1,\ldots,r_i$ in this order to the end of $X$.

Find the greatest length of a strictly increasing subsequence of the final $X$.

Constraints

• $1 \leq N \leq 2 \times 10^5$
• $1 \leq l_i \leq r_i \leq 10^9$
• All values in the input are integers.

Input

The input is given from Standard Input in the following format:

N
l_1 r_1
\vdots
l_{N} r_{N}

Output

Print the answer.