217.cpp

#include <vector>
#include <stdio.h>
#include <algorithm>

int main() {
//  Открываем файлы:
    freopen("input.txt", "rt", stdin);
    freopen("output.txt", "wt", stdout);

//  Читаем данные:
    int count_trees;
    scanf("%d", &count_trees);

    std::vector<int> w(count_trees), e(count_trees);

    for (int i = 0; i < count_trees; ++i)
        scanf("%d %d", &w[i], &e[i]);

    int count_pos;
    scanf("%d", &count_pos);

    std::vector<int> x(count_pos);

    for (auto & it : x)
        scanf("%d", &it);

//  Решаем задачу двумерным ДП:
    std::vector<std::vector<int>> max(count_pos, std::vector<int>(count_trees, 1));

    for (int last_pos = 1; last_pos < count_pos; ++last_pos)
        for (int last_tree = 0; last_tree < count_trees; ++last_tree)
            for (int prev_pos = 0; prev_pos < last_pos; ++prev_pos)
                for (int prev_tree = 0; prev_tree < count_trees; ++prev_tree) {
                    if (
                        x[prev_pos] + e[prev_tree] <= x[last_pos] &&
                        x[prev_pos] + w[last_tree] <= x[last_pos] &&
                        max[last_pos][last_tree] < max[prev_pos][prev_tree]+1
                    )
                        max[last_pos][last_tree] = max[prev_pos][prev_tree]+1;
                }

//  Выводим ответ: максимум среди элементов последнего столбца (последней клумбы):
    printf("%d", *max_element(max.back().begin(), max.back().end()));

    return 0;
}