#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;

int main() {

    int n;
    cin >> n;

    vector<ll> p1m, p2m;
    for (int i = 0; i < n; i++) {
        ll y;
        cin >> y;
        if (y > 0) {
            p1m.push_back(y);
        } else {
            p2m.push_back(abs(y));
        }
    }

    vector<ll> p1f, p2f;
    for (int i = 0; i < n; i++) {
        ll y;
        cin >> y;
        if (y > 0) {
            p1f.push_back(y);
        } else {
            p2f.push_back(abs(y));
        }
    }

    sort(p1m.begin(), p1m.end());
    sort(p2m.begin(), p2m.end());
    sort(p1f.begin(), p1f.end());
    sort(p2f.begin(), p2f.end());

    int cnt = 0;

    ll i = 0, j = 0;
    while (i < p1m.size() && j < p2f.size()) { // female wants small males
        if (p2f[j] > p1m[i]) {
            cnt++;
            i++;
            j++;
        } else {
            j++;
        }
    }

    i = 0;
    j = 0;
    while (i < p2m.size() && j < p1f.size()) { // male wants small females
        if (p2m[i] > p1f[j]) {
            cnt++;
            i++;
            j++;
        } else {
            i++;
        }
    }

    cout << "Valid Pairs: " << cnt;
    return 0;
}