B0053.cpp

// Problem Code: KTTABLE

#include <iostream>
#include <vector>

using namespace std;

int kitchenTimetable(vector<int> A, vector<int> B) {
	int count = (B[0] <= A[0]) ? 1 : 0;
	for(int i=1 ; i<A.size() ; i++)
		if(B[i] <= A[i] - A[i-1])
			count++;
	return count;
}

int main() {
	int T, N, num;
	vector<int> A, B;
	cin >> T;
	while(T--) {
		cin >> N;
		for(int i=0 ; i<N ; i++) {
			cin >> num;
			A.push_back(num);
		}
		for(int j=0 ; j<N ; j++) {
			cin >> num;
			B.push_back(num);
		}
		cout << kitchenTimetable(A, B) << endl;
		A.clear();
		B.clear();
	}
	return 0;
}