#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;

#define sz(x) (int)(x).size()
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pii;
typedef pair<ll,ll> pll;
typedef pair<ld,ld> pdd;

struct int_hash {
    static uint64_t splitmix64(uint64_t x) {
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

struct pair_hash {
    size_t operator()(pii x) const {
        return int_hash{}(x.first) ^ (int_hash{}(x.second) << 16);
    }
};

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<cd> vcd;
typedef vector<vector<int>> vvi;
typedef vector<vector<ll>> vvl;
typedef vector<vector<pii>> vvpii;
typedef vector<vector<pll>> vvpll;
typedef unordered_map<int, int, int_hash> umpii;
typedef unordered_map<ll, ll, int_hash> umpll;
typedef unordered_set<int, int_hash> usi;
typedef unordered_set<ll, int_hash> usll;
typedef unordered_set<pii, pair_hash> uspii;
typedef queue<int> qi;
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int MOD = 1000000007;
const ll INF = numeric_limits<ll>::max();
const int inf = numeric_limits<int>::max();
const int MX = 100001; //check the limits, dummy

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    int n; cin >> n;
    vpii v(n, {0, 0}); 
    F0R(i, n) {
        cin >> v[i].f;
        cin >> v[i].s;
    }

    sort(v.begin(), v.end(), [](const pii &p1, const pii &p2){ return p1.f + p1.s < p2.f + p2.s; });
    vvi dp(n + 1, vi(n + 1, inf));
    dp[0][0] = 0;
    int ans = 0;
    F0R(i, n) {
        F0R(j, i + 1) {
            dp[i + 1][j + 1] = min(dp[i][j + 1], v[i].f >= dp[i][j] ? dp[i][j] + v[i].s : inf);
            ans = max(ans, dp[i + 1][j + 1] == inf ? 0 : j + 1);
        }
    }

    cout << ans << endl;
}


#include <algorithm>
#include <cassert>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
/* #include <regex> */

using namespace std;

/* g++ -g -std=c++11 */

/* freopen("input.txt", "rt", stdin); */
/* freopen("output.txt", "wt", stdout); */

#define ALL(c)          (c).begin(), (c).end()
#define ALLR(c)         (c).rbegin(), (c).rend()
#define FOR(i,a,b)      for (int i=(a); i < (b); ++i)
#define FORR(i,a,b)     for (int i=(a); i > (b); --i)
#define FOR_ALL(i,c)    for (__typeof((c).begin()) i=(c).begin();   \
                             i != (c).end(); ++i)
#define FOR_ALLR(i,c)   for (__typeof((c).rbegin()) i=(c).rbegin(); \
                             i != (c).rend(); ++i)
#define SZ(array)       (sizeof(array)/sizeof(array[0]))
#define lc(x)           (x<<1)     /* 2*x */
#define rc(x)           (x<<1 | 1) /* 2*x+1 */
#define lowbit(x)       (x & (-x)) /* 0b10100 -> 0b100 */

typedef long long       LL;
typedef map<int,int>    MII;
typedef pair<int,int>   PII;
typedef set<int>        SI;
typedef vector<bool>    VB;
typedef vector<double>  VD;
typedef vector<int>     VI;
typedef vector<string>  VS;

/* check if a key is in container C */
template <class C>
inline bool in_(const typename C::key_type& k, const C& A)
{ return A.find(k) != A.end(); }
inline bool in_(const string& s, const string& S)
{ return S.find(s) != string::npos; }

const LL inf = 1e16;
VI H,P, sorted; 

bool cmp(const int i, const int j)
{ return H[i]+P[i] < H[j]+P[j]; }

int main()
{
#ifdef foo_
    freopen("foo", "rt", stdin);
#endif
    ios::sync_with_stdio(false);
    int n;
    while (cin >> n) {
        H = P = sorted = VI(n);
        FOR(i,0,n) {
            cin >> H[i] >> P[i];
            sorted[i] = i;
        }
        sort(ALL(sorted),cmp);
        vector<LL> dp = vector<LL>(n+1,inf);
        dp[0] = 0; int ans = 0;
        FOR(i,0,n) {
            const int j = sorted[i];
            FORR(x,n-1,-1) if (dp[x] != inf && dp[x] <= H[j]) {
                dp[x+1] = min(dp[x+1], dp[x]+P[j]);
                ans = max(ans, x+1);
            }
        }
        cout << ans << endl;
    }
    return 0;
}
