#include<bits/stdc++.h>

using namespace std;

#define int long long


signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int n, m;
    cin >> n;
    vector<int> v(n);
    for (int i = 0; i < n; i++) {
        cin >> v[i];
    }
    cin >> m;
    vector<int> d(m);
    for (int i = 0; i < m; i++) {
        cin >> d[i];
    }
    sort(v.begin(), v.end());
    sort(d.begin(), d.end());
    int l = 0, r = 0, ans = 0;
    while(l < n && r < m) {
        while(abs(v[l] - d[r]) <= 1 && l < n && r < m){
            ++ans;
            ++l;
            ++r;
        }
        if(l <= r){
            l++;
        }else{
            r++;
        }
    }
    cout << ans;
}