/* ---------- STL Libraries ---------- */

// IO library
#include <cstdio>
#include <fstream>
#include <iomanip>
#include <ios>
#include <iostream>

// algorithm library
#include <algorithm>
#include <cmath>
#include <numeric>
#include <random>

// container library
#include <array>
#include <bitset>
#include <deque>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <tuple>
#include <vector>

/* ---------- Namespace ---------- */

using namespace std;

/* ---------- Type Abbreviation ---------- */

template <typename T>
using PQ = priority_queue<T>;
template <typename T>
using GPQ = priority_queue<T, vector<T>, greater<T>>;

using ll = long long;

#define fst first
#define snd second
#define mp make_pair
#define mt make_tuple

/* ---------- conversion ---------- */

#define INT(c) static_cast<int>(c)
#define CHAR(n) static_cast<char>(n)
#define LL(n) static_cast<ll>(n)
#define DOUBLE(n) static_cast<double>(n)

/* ---------- container ---------- */

#define ALL(v) (v).begin(), (v).end()
#define SIZE(v) (LL((v).size()))

#define FIND(v, k) (v).find(k) != (v).end()
#define VFIND(v, k) find(ALL(v), k) != (v).end()

#define gsort(b, e) sort(b, e, greater<decltype(*b)>())

/* ----------- debug ---------- */

template <class T>
ostream& operator<<(ostream& os, vector<T> v) {
    os << "[";
    for (auto vv : v)
        os << vv << ",";
    return os << "]";
}

template <class T>
ostream& operator<<(ostream& os, set<T> v) {
    os << "[";
    for (auto vv : v)
        os << vv << ",";
    return os << "]";
}

template <class L, class R>
ostream& operator<<(ostream& os, pair<L, R> p) {
    return os << "(" << p.fst << "," << p.snd << ")";
}

/* ---------- Constants ---------- */

// const ll MOD = 1e9 + 7;
// const int INF = 1 << 25;
const ll INF = 1LL << 50;
// const double PI = acos(-1);
// const double EPS = 1e-10;
// mt19937 mert(LL(time(0)));

/* ---------- Short Functions ---------- */

template <typename T>
T sq(T a) {
    return a * a;
}

template <typename T>
T gcd(T a, T b) {
    if (a > b) return gcd(b, a);
    return a == 0 ? b : gcd(b % a, a);
}

template <typename T, typename U>
T mypow(T b, U n) {
    if (n == 0) return 1;
    if (n == 1) return b /* % MOD */;
    if (n % 2 == 0) {
        return mypow(b * b /* % MOD */, n / 2);
    } else {
        return mypow(b, n - 1) * b /* % MOD */;
    }
}

ll pcnt(ll b) {
    return __builtin_popcountll(b);
}

/* v-v-v-v-v-v-v-v-v Main Part v-v-v-v-v-v-v-v-v */

bool sumcmp(const pair<int, int>& a, const pair<int, int>& b) {
    return a.first + a.second < b.first + b.second;
}

ll dp[5010][5010];

int main() {
    int N;
    cin >> N;

    pair<ll, ll> hp[N];
    for (int i = 0; i < N; ++i) {
        cin >> hp[i].first >> hp[i].second;
    }
    sort(hp, hp + N, sumcmp);

    fill(dp[0], dp[0] + N + 1, INF);
    dp[0][0] = 0, dp[0][1] = hp[0].second;
    // dp[i][j] = i人目まででj人を選んだときの,Pの総和の最小値
    // 0人目は絶対置けるので初期化

    for (int i = 1; i < N; ++i) {
        // i人目を選ばない場合
        for (int j = 0; j <= N; ++j) {
            dp[i][j] = dp[i - 1][j];
        }

        // i人目を選ぶ場合
        for (int j = 0; j < N; ++j) {
            if (dp[i - 1][j] <= hp[i].first) {
                dp[i][j + 1] = min(dp[i][j + 1], dp[i - 1][j] + hp[i].second);
            }
        }
    }

    int ans = 0;
    for (int j = 0; j <= N; ++j) {
        if (dp[N - 1][j] < INF) ans = j;
    }

    cout << ans << endl;
    return 0;
}


Measured memory_bytes: 195968