#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define SPEED ios_base::sync_with_stdio(false); cin.tie(NULL);
#define FOR(i, a, b) for (ll i = a; i < b; ++i)
#define RFOR(i, b, a) for (ll i = b; i >= a; --i)
#define ALL(x) x.begin(), x.end()
#define DEBUG(args...) { string _s = #args; replace(ALL(_s), ' ', '\0');\
replace(ALL(_s), ',', ' ');\
stringstream _ss(_s); istream_iterator<string> _it(_ss); _debug(_it, args);}
#define endl "\n"
#define F first
#define S second
#define pb(x) push_back(x)
#define mp(x, y) make_pair(x, y)

using namespace std;
using namespace __gnu_pbds;

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

void _debug(istream_iterator<string>) {}
template<typename T, typename... Args>
void _debug(istream_iterator<string> it, T first, Args... args) {
    cerr << ">> " << *it << " : " << first << endl; _debug(++it, args...);
}
template <typename T1, typename T2>
inline ostream& operator << (ostream& out, const pair<T1, T2>& p) {
    return out << "(" << p.F << ", " << p.S << ")";
}
template<typename T>
inline ostream& operator << (ostream& out, const vector<T>& v) {
    if (v.empty()) return out << "[]";
    else { out << '['; for (auto& e : v) { out << e << ", "; } return out << "\b\b]"; }
}
template<typename T>
inline ostream& operator << (ostream& out, const set<T>& s) {
    if (s.empty()) return out << "{}";
    else { out << '{'; for (auto& e : s) { out << e << ", "; } return out << "\b\b}"; }
}
template<typename T>
inline ostream& operator << (ostream& out, const unordered_set<T>& s) {
    return out << set<T>(ALL(s));
}
template<typename T1, typename T2>
inline ostream& operator << (ostream& out, const map<T1, T2>& m) {
    if (m.empty()) return out << "{}";
    out << '{'; for (auto& p : m) { out << p << ", "; } return out << "\b\b}";
}
template<typename T1, typename T2>
inline ostream& operator << (ostream& out, const unordered_map<T1, T2>& m) {
    return out << map<T1, T2>(ALL(m));
}
template<typename T>
inline ostream& operator << (ostream& out, const ordered_set<T>& s) {
    return out << set<T>(ALL(s));
}

typedef long long ll;
typedef long double ld;
typedef vector<long long> vll;
typedef pair<ll, ll> pll;
typedef vector<pair<ll, ll>> vpll;
typedef unordered_map<ll, ll> STll;
/************************************** MAIN PROGRAM ********************************************/
const long long INF = 1e15;

int main()
{
    //freopen("input.txt", "r", stdin);
	ll n;
	cin >> n;
	vpll arr(n);
	
	FOR(i, 0, n)
	{
		cin >> arr[i].F >> arr[i].S; 
		// first = height of the pile\
		// second = pillows one dude will place on his chance
	}
	
	sort(ALL(arr), [](auto x, auto y) {
		return x.F + x.S < y.F + y.S;
	});
	
	vector<ll> dp(n + 1, INF);
	// dp[pref][used] = the min height that will be there after we use 'used'
	// candidates from prefix of length of pref
	
	dp[0] = 0;
	FOR(i, 1, n + 1)
	{
		RFOR(used, n + 1, 1)
		{
		    ll val = dp[used];
			val = min(val, dp[used]); // don't give current guy a chance
			
			// try to give him a chance
			if (arr[i - 1].F >= dp[used - 1]) {
			    val = min(val, dp[used - 1] + arr[i - 1].S);
			}
			dp[used] = val;
		}
	}
	
	ll ans;
	FOR(used, 1, n + 1) {
	    if (dp[used] != INF) {
	        ans = used;
	    }
	}
	cout << ans;
}
/************************************** END OF PROGRAM ******************************************/

Measured memory_bytes: 384