City line

#include <cstdio>
#include <set>
#include <vector>
#include <algorithm>

int main()
{
    int n = 0;
    std::scanf("%d", &n);
    std::multiset<int> first;

    for (int i = 0; i < n; i++)
    {
        int x = 0;
        std::scanf("%d", &x);
        first.insert(x);
    }

    int m = 0;
    std::scanf("%d", &m);
    std::multiset<int> second;

    for (int i = 0; i < m; i++)
    {
        int x = 0;
        std::scanf("%d", &x);
        second.insert(x);
    }

    if (*second.rbegin() != *first.rbegin())
        std::puts("NO");

    else
    {
        std::vector<int> ans;
        std::set_union(first.begin(), first.end(), second.begin(), second.end(), std::back_inserter(ans));
        std::printf("%llu", ans.size());
    }

    return 0;
}