#include <bits/stdc++.h>

using i32 = std::int32_t;
using u32 = std::uint32_t;
using i64 = std::int64_t;
using u64 = std::uint64_t;
using i128 = __int128_t;
using u128 = __uint128_t;
using isize = std::ptrdiff_t;
using usize = std::size_t;

class rep {
    struct Iter {
        usize itr;
        constexpr Iter(const usize pos) noexcept : itr(pos) {}
        constexpr void operator++() noexcept { ++itr; }
        constexpr bool operator!=(const Iter& other) const noexcept { return itr != other.itr; }
        constexpr usize operator*() const noexcept { return itr; }
    };
    const Iter first, last;

  public:
    explicit constexpr rep(const usize first, const usize last) noexcept : first(first), last(std::max(first, last)) {}
    constexpr Iter begin() const noexcept { return first; }
    constexpr Iter end() const noexcept { return last; }
};

class revrep {
    struct Iter {
        usize itr;
        constexpr Iter(const usize pos) noexcept : itr(pos) {}
        constexpr void operator++() noexcept { --itr; }
        constexpr bool operator!=(const Iter& other) const noexcept { return itr != other.itr; }
        constexpr usize operator*() const noexcept { return itr; }
    };
    const Iter first, last;

  public:
    explicit constexpr revrep(const usize first, const usize last) noexcept
        : first(last - 1), last(std::min(first, last) - 1) {}
    constexpr Iter begin() const noexcept { return first; }
    constexpr Iter end() const noexcept { return last; }
};

template <class T> bool setmin(T& lhs, const T& rhs) {
    if (lhs > rhs) {
        lhs = rhs;
        return true;
    }
    return false;
}

template <class T, T Div = 2> constexpr T INFTY = std::numeric_limits<T>::max() / Div;

template <class T> using Vec = std::vector<T>;

void main_() {
    usize N;
    std::cin >> N;
    Vec<u32> W(N), S(N);
    for (const auto i : rep(0, N)) {
        std::cin >> W[i] >> S[i];
    }
    Vec<usize> order(N);
    std::iota(order.begin(), order.end(), (usize)0);
    std::sort(order.begin(), order.end(), [&](const usize i, const usize j) { return W[i] + S[i] < W[j] + S[j]; });
    Vec<u32> min(N + 1, INFTY<u32>);
    min[0] = 0;
    for (const auto i : order) {
        for (const auto j : revrep(0, N)) {
            if (S[i] >= min[j]) {
                setmin(min[j + 1], min[j] + W[i]);
            }
        }
    }
    std::cout << std::lower_bound(min.begin(), min.end(), INFTY<u32>) - min.begin() - 1 << '\n';
}

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    main_();
    return 0;
}