Given an array A with 105 elements. Initially all the elements equals 0.
Given N segments in each of the segments your are given 2 integers X and Y you have to increase all the elements of A from X to Y by 1.Now after processing all the N segments your task is to compute how many indices from 1 to 100000 have prime values.
INPUT
First line contains N total number of segments you want to update.
Next N lines contains 2 integers X and Y you have to update each element from X to Y by 1.
OUTPUT
Number of Primes after processing all the segments.
CONSTRAINTS
1≤N≤105
1≤X,Y≤105