#include <bits/stdc++.h>
using namespace std;
struct sr {
    int sl, p;
} b[1010];
bool cmp(sr a, sr b) {
	//先按优先等级排序，再按蛋糕数量小到大 
   if(a.p>b.p||a.p==b.p&&a.sl<b.sl){
        return 1;
   }else{
        return 0;
   }
}
int main() {
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= n; i++) {
        cin >> b[i].sl >> b[i].p;
    }
    sort(b+1, b + n+1, cmp);
    int s = 0;
    for (int i = 1; i <=n; i++) {
    	//能够满足这个人的蛋糕要求 
        if (m >= b[i].sl) {//剩余蛋糕还够
            s += 1;
            m -= b[i].sl;
        }
    }
    cout <<s;
    return 0;
}