const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;
void (async function () {
const [n, m] = (await readline()).split(" ").map(Number);
const foods = [];
for (let i = 0; i < n; i++) {
foods.push(await readline().split(" ").map(Number));
}
const suit = foods.map((food) => food[0] + food[1]).sort((a, b) => a - b);
let res = 1;
let pre = 0;
for (let i = 1; i < suit.length; i++) {
if (suit[i] - suit[pre] >= m) {
res++;
pre = i;
}
}
console.log(res);
})();