import sys

def solve():
    """
    Solves a single test case for the maximum score, minimum size problem.
    """
    n = int(sys.stdin.readline())
    a = list(map(int, sys.stdin.readline().split()))
    b = list(map(int, sys.stdin.readline().split()))

    # Fenwick Tree for Range Maximum Queries
    class MaxBIT:
        def __init__(self, size):
            self.tree = [0] * (size + 1)

        def update(self, idx, val):
            while idx < len(self.tree):
                self.tree[idx] = max(self.tree[idx], val)
                idx += idx & -idx

        def query(self, idx):
            max_val = 0
            while idx > 0:
                max_val = max(max_val, self.tree[idx])
                idx -= idx & -idx
            return max_val

    # 1. Forward pass to find the global maximum score (s_max)
    ft1 = MaxBIT(n)
    s_max = 0
    for i in range(n):
        # Find max score of subsequences ending with a value less than a[i]
        max_prev_score = ft1.query(a[i] - 1)
        current_score = max_prev_score + b[i]
        ft1.update(a[i], current_score)
        s_max = max(s_max, current_score)

    # 2. Backward pass to find the max score for all subsequences starting at i
    suffix_scores = [0] * n
    ft2 = MaxBIT(n)
    for i in range(n - 1, -1, -1):
        # Query for values > a[i] using coordinate transformation
        # Values > k are mapped to transformed indices < n - k + 1
        max_next_score = ft2.query(n - a[i])
        current_score = max_next_score + b[i]
        suffix_scores[i] = current_score
        # Update using the transformed index n - a[i] + 1
        ft2.update(n - a[i] + 1, current_score)

    # 3. Find the latest starting index `k` that can achieve s_max
    max_score_in_suffix = 0
    for k in range(n - 1, -1, -1):
        max_score_in_suffix = max(max_score_in_suffix, suffix_scores[k])
        if max_score_in_suffix == s_max:
            # This is the latest start point, so it gives the minimum size
            print(n - k)
            return

def main():
    """
    Main function to handle multiple test cases.
    """
    try:
        t = int(sys.stdin.readline())
        for _ in range(t):
            solve()
    except (IOError, ValueError):
        # Handles potential empty lines or formatting errors at the end of input
        pass

if __name__ == "__main__":
    main()