我用搜索进了最优解第一页：

#include<bits/stdc++.h>

using namespace std;
int n, iq, eq, len = 1, ans;
array<int, 405> w, v, a, b, c;

void dfs(int i, int x, int y) {
    static int cnt = 0;
    cnt++;
    if (cnt > 100000000) {
        cout << ans;
        exit(0);
    } else if (i == len + 1) {
        if (x >= 0 && y >= 0) {
            ans = max(ans, x + y);
        }
    } else if (x + y + a[i] > ans && x + b[i] >= 0 && y + c[i] >= 0) {
        dfs(i + 1, x + w[i], y + v[i]);
        dfs(i + 1, x, y);
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n;
    for (int i = 1; i <= n; ++i, ++len) {
        int x, y;
        cin >> x >> y;
        if (x + y >= 0) {
            if (x >= 0 && y >= 0) {
                iq += x;
                eq += y;
            } else {
                w[len] = x;
                v[len] = y;
            }
        } else {
            len--;
        }
    }
    for (int i = len; i > 0; --i) {
        a[i] = a[i + 1] + w[i] + v[i];
        b[i] = b[i + 1] + max(0, w[i]);
        c[i] = c[i + 1] + max(0, v[i]);
    }
    ans = iq + eq;
    dfs(1, iq, eq);
    cout << ans;
    return 0;
}