package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	in := bufio.NewReader(os.Stdin)
	var t int
	if _, err := fmt.Fscan(in, &t); err != nil {
		return
	}
	for ; t > 0; t-- {
		var n int
		fmt.Fscan(in, &n)
		a := make([]int, n)
		for i := 0; i < n; i++ {
			fmt.Fscan(in, &a[i])
		}
		b := make([]int, n)
		for i := 0; i < n; i++ {
			fmt.Fscan(in, &b[i])
		}
		i, j := 0, 0
		for i < n && j < n {
			if a[i] <= b[j] {
				i++
			}
			j++
		}
		fmt.Println(n - i)
	}
}