#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>
#include <string>

using namespace std;

int main() {
	int n, k;
	int win = 0;

	for (int i = 0; i < 1000; i++) {
		cin >> n >> k;
		int tmp = (n - 1) % (k + 1);
		if (1 <= tmp && tmp <= k) {
			win++;
		}
	}
	cout << win << endl;
	return 0;
}