Problem Statement

You are given sequences of length $N$ each: $A = (A_1, A_2, A_3, \\dots, A_N)$ and $B = (B_1, B_2, B_3, \\dots, B_N)$.
Find the number of integers $x$ satisfying the following condition:

• $A_i \\le x \\le B_i$ holds for every integer $i$ such that $1 \\le i \\le N$.

Constraints

• $1 \\le N \\le 100$
• $1 \\le A_i \\le B_i \\le 1000$
• All values in input are integers.

Input

Input is given from Standard Input in the following format:

$N$ $A_1$ $A_2$ $A_3$ $\\dots$ $A_N$ $B_1$ $B_2$ $B_3$ $\\dots$ $B_N$

Output

Print the answer.

Sample Input 1

2
3 2
7 5

Sample Output 1

3

$x$ must satisfy both $3 \\le x \\le 7$ and $2 \\le x \\le 5$.
There are three such integers: $3$, $4$, and $5$.

Sample Input 2

3
1 5 3
10 7 3

Sample Output 2

0

There may be no integer $x$ satisfying the condition.

Sample Input 3

3
3 2 5
6 9 8

Sample Output 3

2