Codeforces_Greedy_Level_1

#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,mmx,avx,avx2")
//think twice code once
//when its getting hard remember why you started
# include   <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> pbds;
// find_by_order->iterator to that index, order_of_key->returns no of elements smaller than the key;
#ifdef Mayank
#include "bug.h"
#else
#define bug(...)
#endif
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

typedef pair<int, int> pi;
typedef pair<ll, ll> pl;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;//typedef for datatype and #define for macro
typedef vector<pl> vpl;

# define    fast                ios_base::sync_with_stdio(false);cin.tie(NULL);
# define    MOD                 1000000007
# define    endl                '\n'
# define    FOR(i, a, b)        for (int i=a; i<(b); i++)
# define    F0R(i, a)           for (int i=0; i<(a); i++)
# define    FORd(i,a,b)         for (int i = (b)-1; i >= a; i--)
# define    F0Rd(i,a)           for (int i = (a)-1; i >= 0; i--)
# define    INF                 9e18
# define    PI                  3.14159265358979323846
# define    lb                  lower_bound
# define    ub                  upper_bound
# define    mp                  make_pair
# define    pb                  push_back
# define    fi                  first
# define    se                  second
# define    all(a)              a.begin(), a.end()
# define    iceil(n, x)         (((n) + (x) - 1) / (x))
ll mod_add(ll a, ll b, ll m) {a = a % m; b = b % m; return (((a + b) % m) + m) % m;}
ll mod_mul(ll a, ll b, ll m) {a = a % m; b = b % m; return (((a * b) % m) + m) % m;}
ll mod_sub(ll a, ll b, ll m) {a = a % m; b = b % m; return (((a - b) % m) + m) % m;}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ll lcm(ll a, ll b)
{
	return ((a * b) / __gcd(a, b));
}
// int main()
// {
// 	fast;
// 	ll t;
// 	cin >> t;
// 	while (t--)
// 	{
// 		ll n; cin >> n;
// 		vl v(n); for (ll i = 0; i < n; i++) cin >> v[i];
// 		ll maxsum = 0;
// 		ll i = 0;
// 		while (i < n) {
// 			if (v[i] > 0) {//+ve chunks
// 				ll temp = INT_MIN;
// 				while (i < n && v[i] > 0) {
// 					temp = max(temp, v[i]);
// 					i++;
// 				}
// 				maxsum += temp; continue;
// 			}
// 			if (v[i] < 0) {
// 				ll temp = INT_MIN;
// 				while (i < n && v[i] < 0) {
// 					temp = max(temp, v[i]);
// 					i++;
// 				}
// 				maxsum += temp; continue;
// 			}
// 		}
// 		cout << maxsum << endl;
// 	}
// 	return 0;
// }


int main() {
	fast;

	ll n; cin >> n;
	vl a(n); for (ll i = 0; i < n; i++) cin >> v[i];
	ll m; cin >> m;
	vl b(m); for (ll i = 0; i < m; i++) cin >> b[i];
	sort(all(a)); sort(all(b));
	int i = 0, j = 0, countans = 0;
	while (i < n && j < m) {
		if (abs(a[i] - b[j]) <= 1) {
			countans++; i++; j++;
		}
		else if (a[i] < b[j]) {
			i++;
		}
		else j++;
	}
	cout << countans << endl;
	return 0;
}