Problem:
Search II

You are given a sequence of n integers S and a sequence of different q integers T. Write a program which outputs C, the number of integers in T which are also in the set S.

Input

In the first line n is given. In the second line, n integers are given. In the third line q is given. Then, in the fourth line, q integers are given.

Output

Print C in a line.

Constraints

Elements in S is sorted in ascending order

n ≤ 100000

q ≤ 50000

0 ≤ an element in S ≤ 109

0 ≤ an element in T ≤ 109

Sample Input 1

5
1 2 3 4 5
3
3 4 1

Sample Output 1

3

Sample Input 2

3
1 2 3
1
5

Sample Output 2

0

Sample Input 3

5
1 1 2 2 3
2
1 2

Sample Output 3

2

Notes

Solution in Rust (judge verdict: Accepted)

use std::io::*;
use std::str::FromStr;

fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let stdin = stdin.lock();
    let token: String = stdin
        .bytes()
        .map(|c| c.expect("Failed to read bytes") as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect();
    token.parse().ok().expect("failed to parse token")
}

fn main() {
    let n:usize = read();
    let s:Vec<usize> = (0..n).map(|_| read()).collect();
    let q:usize = read();
    let t:Vec<usize> = (0..q).map(|_| read()).collect();
    let mut ans = 0;
    for i in t {
        ans += binary_search(&s, i);
    }
    println!("{}", ans);
}

fn binary_search(a: & Vec<usize>, key:usize) -> i32 {
    let mut ng = -1;
    let mut ok = a.len() as i32;
    while (ok - ng).abs() >1 {
        let mid = (ok + ng) / 2;
        if a[mid as usize] == key {
            return 1
        }
        if is_ok(&a, mid as usize, key) {
            ok = mid;
        } else {
            ng = mid;
        }
    }
    0
}

fn is_ok(a: &Vec<usize>, index: usize, key:usize) -> bool {
    if a[index] >= key {
        true
    } else {
        false
    }
}